Etymology dictionary

amicability (n.) — amyloid (adj.)

amicability (n.)

"friendliness," 1650s, from amicable + -ity.

"person not interested or employed in a cause who wishes to make a suggestion to the court," 1610s, Latin, literally "friend of the court;" plural is amici curiae. From Latin amicus "friend," related to amare "to love" (see Amy) + curia "court" (see curia).

amid (adv., prep.)

Middle English amidde, from Old English on middan "in the middle," from dative singular of midde "mid, middle" (from PIE root *medhyo- "middle"); also see a- (1). The phrase evidently was felt as "in (the) middle" and thus followed by a genitive case, and if this had endured we would follow it today with of. (See amidst for further evolution along this line).

The same applies to equivalents in Latin (in medio) and Greek (en meso), both originally adjective phrases which evolved to take the genitive case. But in later Old English on middan also was treated as a preposition and followed by dative. Used in compounds from early 13c.

-amide

also amide, in chemical use, 1850, word-forming element denoting a compound obtained by replacing one hydrogen atom in ammonia with an element or radical, from French amide, from ammonia + -ide.

amidships (adv.)

"in or toward the middle of a ship," 1690s, from amid + ship (n.). It retains the genitive -s of compounds of amid in Middle English, suggesting this one is older than the written record of it.

amidst (prep.)

a variant of amid (q.v.) with adverbial genitive -s and unetymological -t. Amidde became amyddes (13c.) and acquired the -t from mid-15c., probably by association with superlatives in -st; the pattern also yielded amongst, against, betwixt, whilst, also archaic alongst (13c.-17c.).

Amiens

cathedral city in northeastern France, Roman Ambianum, named for the Celtic people known as the Ambiani, whose name is from Gaulish *ambe "river" (in reference to the Somme).

amigo (n.)

"friend, comrade," also a form of address, 1837, American English (first attested in the phrase adios, Amigo), from Spanish amigo, literally "friend," from Latin amicus "friend," related to amare "to love" (see Amy).

amine (n.)

"compound in which one of the hydrogen atoms of ammonia is replaced by a hydrocarbon radical," 1863, from ammonia + chemical suffix -ine (2).

amino-

1887 as an element in compound words in chemistry, from combining form of amine. Amino acid is attested from 1898.

amir (n.)

1610s; the same word as emir (q.v.), but generally used of contemporary Indian or Afghan rulers as opposed to historical ones.

Amish (adj.)

1844, American English, from the name of Jacob Amman, 17c. Swiss Mennonite preacher who founded the sect. The surname is a contraction of Old High German ambahtman, title of an official in the German Swiss cantons, from ambet "office" (German Amt; see amt, a Celtic borrowing related to the beginning of ambassador) + man "man." Originally also spelled Omish, which reflects the pronunciation in Pennsylvania German dialect. As a noun, by 1884. Other early names for the sect were Ammanite and, in a European context, Upland Mennonite.

amiss (adv.)

mid-13c., amis "off the mark," also "out of order," literally "on the miss," from a "in, on" (see a- (1)) + missen "fail to hit" (see miss (v.)). From late 14c. as "improper, wrong, faulty;" to take (something) amiss originally (late 14c.) was "to miss the meaning of" (see mistake). Now it means "to misinterpret in a bad sense."

amity (n.)

mid-15c., "friendly relations," especially between nations, from Old French amitie, earlier amistie (13c.) "friendship, affection, love, favor," from Vulgar Latin *amicitatem (nominative *amicitas) "friendship" (source also of Spanish amistad), corresponding to Latin amicitia, from amicus (adj.) "friendly," which ultimately is from amare "to love" (see Amy).

ammeter (n.)

instrument for measuring the strength of electric currents, 1882, from ampere + -meter.

ammo (n.)

1917, shortened form of ammunition.

Ammon

name of the Greek and Roman conception of the Egyptian sovereign sun-god Amun (said to mean literally "hidden"), also Amen-Ra. This they confused with the ram-headed divinity, god of life, worshipped at an oracular sanctuary in Libya. See ammonia. Related: Ammonian.

ammonia (n.)

volatile alkali, a colorless gas with a strong pungent smell, 1799, coined in scientific Latin 1782 by Swedish chemist Torbern Bergman as a name for the gas obtained from sal ammoniac, salt deposits containing ammonium chloride found near temple of Jupiter Ammon in Libya (see Ammon, and compare ammoniac). The shrine was ancient already in Augustus' day, and the salts, traditionally, first were prepared from mineral deposits "from the sands where the camels waited while their masters prayed for good omens" [Shipley, "Origins of English Words"]. Also known as spirit of hartshorn and volatile alkali or animal alkali.

ammoniac (adj.)

late 14c., ammoniak, also armonyak, in reference to certain gums, earths or salts (sal ammoniac) used medicinally and held to have similar properties (see ammonia); from Old French ammoniac, armoniac, ultimately from Greek *ammoniakos, from the god-name Ammon (q.v.).

The gum (Latin guttae ammoniaci) came from a wild plant that grew across North Africa and Asia. The earth (Latin bolus armenicus) was so called because the substance was found in Armenia; hence the medieval forms were confused with words from Greek harmonia (gum ammoniac was used as a binding agent) or Armenia.

ammonite (n.)

"fossil cephalopod mollusk," 1758, from French (Breyn, 1732), "better established" [Century Dictionary] by French zoologist Jean Guillaume Bruguière in 1789, from Medieval Latin (cornu) Ammonis "horn of Ammon," the Egyptian god of life and reproduction (see Ammon), who was depicted with ram's horns, which the fossils resemble. The resemblance also was noted in ancient times. They also were thought to be petrified snakes, hence snakestone.

ammunition (n.)

1620s, "military stores and provisions," from French soldiers' faulty separation of French la munition, as if *l'amunition; from Latin munitionem (nominative munitio) "a fortifying" (see munition).

The mistake in the word perhaps was by influence of French a(d)monition "warning." The error was corrected in French (Modern French munition), but retained in English, with the unetymological double -m- spelling to conform to words in Latin. At first it meant all military supplies in general; in modern use it means only material used in the discharge of firearms and ordnance.

amnemonic (adj.)

"characterized by loss of memory," 1868; see a- (3) + mnemonic.

amnesic (adj.)

"pertaining to amnesia," 1863; see amnesia + -ic.

amnesia (n.)

"loss of memory," 1786 (as a Greek word in English from 1670s), Modern Latin, from Greek amnesia "forgetfulness," from a- "not" (see a- (3)) + mnesi- "remembering" (found only in compounds), from stem of mnasthai "to recall, remember," which is related to mnemnon "mindful," mneme "memory" (from PIE root *men- (1) "to think"). The usual compound in Greek was amnestia, but this had a specialized sense of "forgetfulness of wrong" (see amnesty).

amnesiac (n.)

"one affected by amnesia," 1913 (as an adjective from 1885), from amnesia (q.v.).

amnestic (adj.)

"causing loss of memory," 1861, from Greek amnestia "forgetfulness" (see amnesia) + -ic.

amnesty (n.)

1570s, "a ruling authority's pardon of past offenses," from French amnistie "intentional overlooking" (16c.), from Latin amnestia, from Greek amnestia "forgetfulness (especially of wrong); an amnesty," from amnestos "forgotten; forgetful," from a- "not" (see a- (3)) + mnestis "remembrance," which is related to mnaomai "I remember" (from PIE root *men- (1) "to think").

Usually specifically of pardons or offers of pardon for a class of offenses against a government. As a verb from 1809. Related: Amnestied. The non-governmental organization Amnesty International was founded 1961 to call attention to the plight of prisoners of conscience, as Appeal for Amnesty; the name was changed 1963.

amniocentesis (n.)

diagnostic technique involving the withdrawing of amniotic fluid by hypodermic needle, 1958, Modern Latin, from amnion + centesis "surgical puncture involving a puncture," from Latinized form of Greek kentesis "a pricking," from kentein "to prick" (from PIE root *kent- "to prick, jab;" see center (n.)).

amnion (n.)

"innermost membrane around the embryo of a higher vertebrate" (reptiles, birds, mammals), 1660s, Modern Latin, from Greek amnion "membrane around a fetus," originally "vase in which the blood of a sacrifice was caught," which is of unknown origin; sometimes said to be from amē "bucket," or a diminutive of amnos "lamb."

amniotic (adj.)

1822, from amnion + -ic, perhaps from or based on French amniotique. The form is irregular; a classically correct word would be *amniac.

Amos

masc. proper name; third of the prophets in the Old Testament; via Latin and Greek, from Hebrew Amos, literally "borne (by God)."

amoebae

classically correct plural form of amoeba; see -ae.

amoeba (n.)

type of microscopic protozoa, 1855, from Modern Latin Amoeba, genus name (1841 in English, said to have been used 1830 by German naturalist Christian Ehrenberg), from Greek amoibē "change, alteration; exchange," which is related to ameibein "to change, exchange" (from an extended form of PIE root *mei- (1) "to change, go, move"). So called for its constantly changing shape. An earlier popular name for it was proteus (1660s). Related: Amoebic; amoebiform; amoeboid.

amoebaean (adj.)

also amoebean, "alternating, answering alternately," 1650s, from Greek amoibē "change, alteration; exchange" (see amoeba) + -an.

Amoy

old name for the coastal island of southeastern China now known by the more precise transliteration Xiamen; from local dialect xia "summer" + men "gate." From 1851 as the name of a dialect of Chinese.

amok (adv.)

in run amok a verbal phrase recorded by 1670s, from Malay (Austronesian) amuk "attacking furiously." Earlier the word was used as a noun or adjective meaning "a frenzied Malay," originally in the Portuguese form amouco or amuco.

Compare amuck.

amole (n.)

plant native to Mexico and the southern U.S., by 1831, in a California context, from Mexican Spanish amole, name for various plant-roots used as detergents, from Nahuatl (Aztecan) amolli "soap-root."

among (prep.)

"in, in the midst of," early 12c., from Old English onmang, in late Old English sometimes amang, a contraction of ongemang "among, during," from the phrase on gemang, literally "in the crowd or company (of)," from on (see a- (1)) + gemengan "to mingle." Ths second element is from Proto-Germanic *mangjan "to knead together," which is perhaps from a nasalized form of PIE root *mag- "to knead, fashion, fit."

The collective prefix ge- was dropped 12c. leaving onmong, amang, among. Compare Old Saxon angimang "among, amid;" Old Frisian mong "among."

amongst (prep., adv.)

"among," mid-13c., amonges, from among with adverbial genitive -s. The unetymological -t is attested from 16c. (compare amidst).

amontillado (n.)

variety of sherry wine, 1825, from Spanish amontillado, from a "from" (from Latin ad; see ad-) + Montilla, name of a town in the province of Cordova. Formerly the name of a regional wine.

amorous (adj.)

c. 1300, "in love; inclined to love; sexually attracted," from Old French amoros "loving, in love; lovely" (13c., Modern French amoureux), from Late Latin amorosum, from Latin amor "love, affection, strong friendly feeling; one's beloved," from amare "to love, be in love with; find pleasure in" (see Amy). Related: Amorously; amorousness.

amoral (adj.)

"ethically indifferent," 1882, a hybrid formed from Greek-derived a- "not" (see a- (3)) + moral, which is from Latin. Apparently coined by Robert Louis Stevenson as a differentiation from immoral.

amoretto (n.)

1590s, "a lover," from Italian, literally "little love," a diminutive of amore "love," from Latin amor "love, affection; one's beloved" (see Amy).

The English borrowed forms of this word more than once from the continental languages, perhaps perceiving in them romance or naughtiness lacking in the native words. The earliest is Middle English amorette (c. 1400, from Old French amorete "sweetheart, amorous girl"), which was obsolete by 17c. but revived or reborrowed 1825 as amourette "petty love affair." Also amorado (c. 1600, from Spanish), amoroso (1610s, Italian), and compare Amaretto. The words were applied as well to love sonnets, love-knots, amorous glances, little cupids, etc.

amorphous (adj.)

"shapeless, having no determined form," 1731, from Modern Latin amorphus, from Greek amorphos "without form, shapeless, deformed," from a- "without" (see a- (3)) + morphē "form," a word of uncertain etymology. Related: Amorphously; amorphousness.

amortization (n.)

1670s, in reference to the alienation of lands given to religious orders, noun of action from amortize. Of debts, "extinction (especially by a sinking-fund)," from 1824.

amortize (v.)

late 14c., amortisen, in law, "to alienate lands," also (c. 1400) "to deaden, destroy;" from Old French amortiss-, present-participle stem of amortir "deaden, kill, destroy; give up by right" (12c.), from Vulgar Latin *admortire "to extinguish," from ad "to" (see ad-) + mortus "dead," from Latin mors "death" (from PIE root *mer- "to rub away, harm").

The literal sense "make dead" is obsolete in English. In reference to extinguishing a debt from early 19c. Related: Amortized; amortizing.

amortisation (n.)

chiefly British English spelling of amortization; see -ize.

amortise (v.)

chiefly British English spelling of amortize; for suffix, see -ize. Related: Amortised; amortising.

amount (n.)

"quantity, sum," 1710, from amount (v.). As nouns, Middle English had amountance, amountment.

amount (v.)

late 13c., "to go up, rise, mount (a horse)," from Old French amonter "rise, go up; mean, signify," from amont (adv.) "upward, uphill," literally "to the mountain" (12c.), a contraction of the prepositional phrase a mont, from a (from Latin ad "to;" see ad-) + Latin montem (nominative mons) "mountain" (from PIE root *men- (2) "to project").

The meaning "to rise in number or quality (so as to reach)" is from c. 1300. Compare mount (v.). Related: Amounted; amounting.

amour (n.)

c. 1300, "love," from Old French amor "love, affection, friendship; loved one" (11c.), from Latin amor "love, affection, strong friendly feeling" (sometimes used of feelings for sons or brothers, but it especially meant sexual love), from amare "to love" (see Amy). The accent shifted 15c.-17c. to the first syllable as the word became nativized, then shifted back as the sense "illicit love affair" became primary 17c. and the word was felt to be an imported euphemism.

amour-propre (n.)

1775, French, "sensitive self-love, self-esteem;" see amour and proper.

Middle English had it, translated, as proper love "self-love."

amoxycillin (n.)

1971, contracted from the chemical name, amino-p-hydroxybenzylpenicillin; see amino- + oxy- + penicillin.

amp (n.)

1886 as an abbreviation of ampere; 1967 as an abbreviation of amplifier.

ampere (n.)

1881, "the current that one volt can send through a resistance of one ohm," from French ampère, named for French physicist André-Marie Ampère (1775-1836). Adopted by the Electric Congress at Paris in 1881. Shortened form amp is attested from 1886.

amperage (n.)

strength of an electric current, 1889, from ampere, on the model of voltage; see -age.

ampersand (n.)

1797, contraction of and per se and, meaning "(the character) '&' by itself is 'and' " (a hybrid phrase, partly in Latin, partly in English). An earlier form of it was colloquial ampassy (1706). The distinction is to avoid confusion with & in such formations as &c., a once-common way of writing etc. (the et in et cetera is Latin for "and"). The letters a, I, and o also formerly (15c.-16c.) sometimes were written a per se, etc., especially when standing alone as words.

The symbol is based on the Latin word et "and," and comes from an old Roman system of shorthand signs (ligatures) attested in Pompeiian graffiti, and not (as sometimes stated) from the Tironian Notes, a different system of shorthand, probably invented by Cicero's companion Marcus Tullius Tiro. It used a different symbol, something like a reversed capital gamma, to indicate et. This Tironian symbol was maintained by some medieval scribes, including Anglo-Saxon chroniclers, in whose works a symbol resembling a numeral 7 indicates the word and.

In old schoolbooks the ampersand was printed at the end of the alphabet and thus by 1880s the word ampersand had acquired a slang sense of "posterior, rear end, hindquarters."

amphetamine (n.)

"synthetic heart-stimulating drug," 1938, contracted from alphamethyl-phenethylamine.

amphi-

before a vowel amph-, word-forming element meaning "on both sides, of both kinds; on all sides, all around," from Greek amphi (prep., adv.) "round about, on both sides of, all around; about, regarding," which is cognate with Latin ambi-, both from PIE root *ambhi- "around."

amphibious (adj.)

1640s, "combining two qualities; having two modes of life," especially "living both on land and in water," from Latinized form of Greek amphibios "having a double life; living on land and in water" (see amphibian (adj.)). Of motor vehicles, from 1915.

amphibian (n.)

"one of the class of animals between fishes and reptiles, having gills and living in water in the early stage of life, later living on land," 1835; from amphibian (adj.). Amphibia was used in this sense from c. 1600.

amphibian (adj.)

1630s, "having two modes of existence; of doubtful nature," from Greek amphibia, neuter plural of amphibios "living a double life," from amphi "of both kinds" (see amphi-) + bios "life" (from PIE root *gwei- "to live").

Formerly used by zoologists to describe any sort of animal at home on land and in the water, including crocodiles, walruses, beavers, seals, hippopotamuses; the restriction to the class of animals between fishes and reptiles with life cycles that begin in water and mature on land is from 1835.

amphibrach (n.)

in prosody, a foot of three syllables, the middle long, the first and last short; 1580s, from Latin amphibrachus, from Greek amphibrakhys, name for a foot consisting of a long syllable between two short, literally "short at both ends," from amphi "on both sides" (see amphi-) + brakhys "short" (from PIE root *mregh-u- "short"). Related: Amphibrachic.

Amphictyonic (adj.)

in reference to one of several ancient Greek confederations of neighboring states, 1753, probably via French, from Latinized form of Greek amphiktionikos, from amphiktionēs "neighbors," literally "they that dwell round about," from amphi "on both sides, all around" (from PIE root *ambhi- "around") + second element related to ktizein "to create, found," ktoina "habitation, township" (from metathesized form of PIE root *tkei- "to settle, dwell, be home").

The most famous was that of Delphi. Madison and other U.S. Founders devoted close study to it. Shaftesbury has amphictyonian (1711).

amphigory (n.)

"burlesque nonsense writing or verse," 1809, from French amphigouri (18c.), which is of unknown origin, perhaps itself a nonsense word, though the first element seems to suggest Greek amphi (see amphi-). The second sometimes is said to be somehow from Greek gyros "circle," making the whole thus "circle on both sides," or it may be from Greek -agoria "speech" (as in allegory, category). Related: Amphigoric.

amphisbaena (n.)

fabled serpent of ancient times, with a head at either end, late 14c., amphibena, from Medieval Latin, from Greek amphisbaena, from amphis "both ways" (see amphi-) + stem of bainein "to go, walk, step" (from PIE root *gwa- "to go, come").

Amphiscians (n.)

"inhabitants of torrid zones," in ancient geography, 1620s, from Medieval Latin Amphiscii, from Greek amphiskioi "inhabitants of the tropics," literally "throwing a shadow both ways," from amphi "on both sides" (from PIE root *ambhi- "around") + skia "shadow, shade" (see Ascians). So called because they are "people whose shadow is sometimes to the North, and sometimes to the South" [Cockerham, 1623] depending on the sun being below or above the equator. Compare Ascians.

amphitheater (n.)

late 14c., "ancient Roman edifice for the exhibition of games, etc.," from Latin amphitheatrum, from Greek amphitheatron "double theater, amphitheater," neuter of amphitheatros "with spectators all around," from amphi "on both sides" (from PIE root *ambhi- "around") + theatron "theater" (see theater). Classical theaters were semi-circles, thus two together made an amphi-theater. They were used by the Romans especially for gladiatorial contests and combats of wild beasts.

amphitheatre (n.)

chiefly British English spelling of amphitheater. See -er.

Amphitrite

Greek sea-nymph, wife of Poseidon; the first element appears to be amphi "round about, on both sides, all around" (see amphi-), the second trite, fem of tritos "third," but the sense intended by the compound is unclear.

amphora (n.)

early 14c., "two-handled vessel for holding wine, oil, etc.," from Latin amphora from Greek amphoreus "an amphora, jar with two handles, urn," a contraction of amphiphoreus, literally "two-handled," from amphi "on both sides" (see amphi-) + phoreus "bearer," from pherein "to bear" (from PIE root *bher- (1) "to carry").

Decorative amphorae were used as ornaments and given as prizes at some public games. Also a liquid measure in the ancient world, in Greece equal to 9 gallons, in Rome to 6 gallons, 7 pints. Related: Amphoral; amphoric.

amphoteric (adj.)

of a chemical compound, "capable of reacting either as an acid or as a base," 1832, from Greek amphoteros "each or both of two," a variant of amphō "both" that replaced the earlier word. It is identical with Latin ambo and ultimately from the source of amphi- (q.v.). Other languages have the word without the nasal (Old Church Slavonic oba, Lithuanian abu) and Germanic has it without the initial vowel (Gothic bai). De Vaan writes, "There is no overall explanation for the forms, but connection with [amphi] seems clear."

ample (adj.)

mid-15c., "great, abundant," especially "sufficient for any purpose," from Old French ample "large, wide, vast, great" (12c.), from Latin amplus "large, spacious; abundant, numerous; magnificent, distinguished," which is related to ampla "handle, grip; opportunity," from Proto-Italic *amlo- "seizable," from a PIE root meaning "to grab" that also is postulated as the source of amare "to love" (see Amy).

amply (adv.)

"fully, sufficiently, copiously," 1550s, from ample + -ly (2).

amplification (n.)

1540s, "enlargement" in any dimension, from Latin amplificationem (nominative amplificatio) "a widening, extending," noun of action from past-participle stem of amplificare "to enlarge, broaden, increase," from amplus "large" (see ample) + combining form of facere "to make, do" (from PIE root *dhe- "to set, put"). Originally in English often of rhetorical devices; the meaning "enlargement of sound by electrical technology" is from 1915.

amplify (v.)

early 15c., "to enlarge, expand, increase," from Old French amplifier (15c.), from Latin amplificare "to enlarge," from amplus "large" (see ample) + combining form of facere "to make, do" (from PIE root *dhe- "to set, put"). The meaning "augment in volume or amount" is from 1570s. The restriction of use to sound seems to have emerged from c. 1915 in reference to radio technology.

amplifier (n.)

1540s; agent noun from amplify. Electronic sense is from 1914; shortened form amp is from 1967. Alternative stentorphone (1921) did not catch on.

amplitude (n.)

1540s, "state or quality of being ample," from French amplitude or directly from Latin amplitudinem (nominative amplitudo) "wide extent, width," from amplus "large, spacious" (see ample). Amplitude modulation in reference to radio wave broadcast (as opposed to frequency modulation) is first attested 1921, usually abbreviated A.M. Related: Amplitudinous.

ampoule (n.)

"small bottle or flask," especially one used for holy liquids, c. 1200, from Old French ampole "flask, vial," from Latin ampulla "small globular flask or bottle," which is of uncertain origin, perhaps a contracted form of amphora. Superseded in English by the form ampulla and later ampul.

ampul (n.)

1907, "sealed container holding a dose of medicine," from French ampul (1886), from Latin ampulla "flask, vial" (see ampoule). A modern borrowing of the word represented by Middle English ampoule. Related: Ampullaceous.

ampulla (n.)

type of globular ancient Roman bottle with a narrow neck, late 14c., from Latin ampulla (see ampoule, which is the same word come up through French).

amputate (v.)

1630s, "to cut off a limb," originally in English both of plants and persons; a back-formation from amputation or else from Latin amputatus, past participle of amputare "to cut off, lop off; cut around, to prune," from am(bi)- "around" (from PIE root *ambhi- "around") + putare "to prune, trim" (from PIE root *pau- (2) "to cut, strike, stamp"). Related: Amputated; amputating.

amputation (n.)

1610s, "a cutting off of tree branches, a pruning," also "operation of cutting off a limb, etc., of a body," from French amputation or directly from Latin amputationem (nominative amputatio), noun of action from past-participle stem of amputare "to cut off, lop off; cut around, to prune," from am(bi)- "around" (from PIE root *ambhi- "around") + putare "to prune, trim" (from PIE root *pau- (2) "to cut, strike, stamp").

amputee (n.)

"person who has undergone the amputation of a limb," 1910, perhaps on a French model; see amputation + -ee.

Amritsar

city in Punjab, from Sanskrit amrta "immortal" (from a- "not," from PIE root *ne-, + mrta "dead," from PIE root *mer- "to rub away, harm") + saras "lake, pool."

Amsterdam

principal city of the Netherlands; the name is a reference to the dam (see dam (n.1)) built on the Amstel river. The river name is said to be from Germanic elements ama "current" and stelle "place." Prevalence of dam in Dutch place names (Rotterdam, Edam, etc.) reflects the geography of Holland. In rhyming slang, "ram" (e.g. for one who "butts in" a queue).

amt (n.)

territorial division in Denmark and Norway, from Danish amt, from German Amt "office," from Old High German ambaht, a word of Celtic origin related to Gallo-Roman ambactus "servant" (see ambassador).

amtrac (n.)

amphibious assault vehicle, 1944, contraction of amphibious tractor (n.).

Amtrak

U.S. government-run railway corporation, 1971, contraction of American Track.

amuck (adv.)

17c., variant of amok; treated as a muck by Dryden, Byron, etc., and defended by Fowler, who considered amok didacticism.

amulet (n.)

mid-15c., amalettys, from Latin amuletum (Pliny) "thing worn superstitiously as a charm against spells, disease, etc.," which is of uncertain origin, perhaps related to amoliri "to avert, to carry away, remove." OED rejects Arabic origin. Not recorded again in English until c. 1600; the 15c. use may be via French. Related: Amuletic.

amuse (v.)

late 15c., "to divert the attention, beguile, delude," from Old French amuser "fool, tease, hoax, entrap; make fun of," literally "cause to muse" (as a distraction), from a "at, to" (from Latin ad, but here probably a causal prefix) + muser "ponder, stare fixedly" (see muse (v.)).

The original English senses are obsolete; the meaning "divert from serious business, tickle the fancy of" is recorded from 1630s, but through 18c. the primary meaning was "deceive, cheat" by first occupying the attention. "The word was not in reg. use bef. 1600, and was not used by Shakespere" [OED]. Bemuse retains more of the original meaning. Greek amousos meant "without Muses," hence "uneducated."

amusement (n.)

1640s, "diversion of attention," especially in military actions, from French amusement, noun of action from amuser (see amuse).

Meaning "a pastime, play, game, anything which pleasantly diverts the attention" (from duty, work, etc.) is from 1670s, originally depreciative; the meaning "pleasurable diversion" is attested from 1690s. Amusement hall is by 1862; amusement park is attested by 1897.

amused (adj.)

c. 1600, "distracted, diverted, cheated;" 1727 as "entertained;" past-participle adjective from amuse (v.).

amusing (adj.)

1590s, "cheating;" present-participle adjective from amuse (v.). The sense of "interesting" is from 1712; that of "pleasantly entertaining, tickling to the fancy" is by 1826. It was noted late 1920s as a vogue word. Amusive has been tried in all senses since 18c. and might have been useful had it survived. Related: Amusingly; amusingness.

amusable (adj.)

"capable of being amused," 1829 (from 1817 as a French word in English), from amuse (v.) + -able.

amygdala (n.)

part of the brain, from Latin amygdalum "almond" (which the brain parts resemble), from Greek amygdalē "almond" (see almond). English had also amygdales "the tonsils" (early 15c.), from a secondary sense of the Latin word in Medieval Latin, a translation of Arabic al-lauzatani "the two tonsils," literally "the two almonds," so called by Arabic physicians for fancied resemblance.

amyl (n.)

hydrocarbon radical, 1850 (amyle), from Latin amylum "starch," from Greek amylon "fine meal, starch," noun use of neuter of adjective amylos "not ground at the mill," that is, "ground by hand," from a- "not" (see a- (3)) + myle "mill" (from PIE root *mele- "to crush, grind"). So called because it was first obtained from the distilled spirits of potato or grain starch (though it also is obtained from other sources). In 16c. English amyl meant "starch, fine flour."