Agnus Dei Look up Agnus Dei at Dictionary.com
Latin, literally "lamb of God." Latin agnus is from from PIE *agwh-no- "lamb" (see yean) For deus "god," see Zeus.
ago (adj.) Look up ago at Dictionary.com
early 14c., shortened form of Old English agan, agone "departed, passed away," past participle of an obsolete verb ago "to go forth," formed from a- "away" (perhaps here used as an intensive prefix) + gan "go" (see go (v.)). Agone remains a dialectal variant.
agog (adj., adv.) Look up agog at Dictionary.com
"in a state of desire; in a state of imagination; heated with the notion of some enjoyment; longing" [Johnson], c.1400, perhaps from Old French en gogues "in jest, good humor, joyfulness," from gogue "fun," of unknown origin.
agonist (n.) Look up agonist at Dictionary.com
1876, in writings on Greek drama, from Greek agonistes, literally "combatant in the games" (see agony).
agonize (v.) Look up agonize at Dictionary.com
1580s, "to torture," from Middle French agoniser or directly from Medieval Latin agonizare, from Greek agonizesthai "contend in the struggle" (see agony). Intransitive sense of "suffer physical pain" is recorded from 1660s. That of "to worry intensely" is from 1853. Related: Agonized; agonizing.
agony (n.) Look up agony at Dictionary.com
late 14c., "mental suffering" (especially that of Christ in the Garden of Gethsemane), from Old French agonie, agoine "anguish, terror, death agony" (14c.), and directly from Late Latin agonia, from Greek agonia "a (mental) struggle for victory," originally "a struggle for victory in the games," from agon "assembly for a contest," from agein "to lead" (see act (n.)). Sense of "extreme bodily suffering" first recorded c.1600.
agora (n.) Look up agora at Dictionary.com
"assembly place," 1590s, from Greek agora "open space" (typically a marketplace), from ageirein "to assemble," from PIE root *ger- "to gather" (see gregarious).
agoraphobia (n.) Look up agoraphobia at Dictionary.com
"fear of open spaces," 1873, from German Agorophobie, coined 1871 by Berlin psychiatrist Carl Westphal (1833-1890) from Greek agora "open space" (see agora) + -phobia "fear." Related: Agoraphobe; agoraphobic.
agrarian (adj.) Look up agrarian at Dictionary.com
1610s, "relating to the land," from Middle French loy agrarienne "agrarian law," corresponding to Latin Lex agraria, the Roman law for the division of conquered lands, from agrarius "of the land," from ager (genitive agri) "a field," from PIE *agro- (cognates: Greek agros "field," Gothic akrs, Old English æcer "field;" see acre). Meaning "having to do with cultivated land" first recorded 1792.
agree (v.) Look up agree at Dictionary.com
late 14c., "to be to one's liking;" also "to give consent," from Old French agreer "to receive with favor, take pleasure in" (12c.), from phrase a gré "favorably, of good will," literally "to (one's) liking," from Latin ad "to" (see ad-) + gratum "pleasing," neuter of gratus (see grace (n.)); the original sense survives best in agreeable. Meaning "to be in harmony in opinions" is from late 15c. Related: Agreed; agreeing.
agreeable (adj.) Look up agreeable at Dictionary.com
late 14c., "to one's liking," from Old French agreable (12c., Modern French agréable) "pleasing, in agreement, consenting, thankful," from agreer "to please" (see agree). Related: Agreeably. To do the agreeable (1825) was to "act in a courteous manner."
agreeance (n.) Look up agreeance at Dictionary.com
1530s, from Middle French agréance, noun of action from agréer (see agree).
agreement (n.) Look up agreement at Dictionary.com
late 14c., "mutual conformity of things;" c.1400, "mutual understanding" (among persons), also (of things) "mutual conformity," from Old French agrement, noun of action from agreer "to please" (see agree).
agribusiness (n.) Look up agribusiness at Dictionary.com
1955, compound formed from agriculture + business.
agricultural (adj.) Look up agricultural at Dictionary.com
1776, from agriculture + -al (1). Related: Agriculturally; agriculturalist.
agriculture (n.) Look up agriculture at Dictionary.com
mid-15c., from Late Latin agricultura "cultivation of the land," compound of agri cultura "cultivation of land," from agri, genitive of ager "a field" (see acre) + cultura "cultivation" (see culture (n.)). In Old English, the idea could be expressed by eorðtilþ.
agriology (n.) Look up agriology at Dictionary.com
study of prehistoric human customs, 1878, from agrio-, from Greek agrios "wild," literally "living in the fields," from agros "field" (see acre) + -logy. Related: Agriologist (n.), 1875.
agro- Look up agro- at Dictionary.com
word-forming element meaning "pertaining to agriculture or cultivation," from Greek agro-, comb. form of agros "field" (see acre).
agronomy (n.) Look up agronomy at Dictionary.com
"science of land management for crop production," 1814, from French agronomie, from Greek agronomos "overseer of land," from agros "field" (see acre) + -nomos "law or custom, administering," related to nemein "manage" (see numismatic). Related: Agronomist; agronomic.
aground (adv.) Look up aground at Dictionary.com
late 13c., "on the ground," from a- "on" (see a- (1)) + ground (n.). Of ships and boats, "stranded," from c.1500.
ague (n.) Look up ague at Dictionary.com
"malarial fever," c.1300, from Old French ague "acute fever," from Medieval Latin (febris) acuta "sharp (fever)," with fem. of acutus "sharp" (see acute).
ah Look up ah at Dictionary.com
mid-15c., an expression of surprise, delight, disgust, or pain in nearly all Indo-European languages, but not found in Old English (where the equivalent expression was la!), so perhaps from Old French a "ah!, oh! woe!"
aha Look up aha at Dictionary.com
exclamation of surprise or delighted discovery, late 14c., from ah + ha.
They crieden out! ... A ha the fox! and after him thay ran. [Chaucer]
ahead (adv.) Look up ahead at Dictionary.com
1620s, "at the head, in front," from a- "on" (see a- (1)) + head (n.). Originally nautical. To be ahead of (one's) time attested by 1837.
ahem Look up ahem at Dictionary.com
attention-getting interjection, 1763, lengthened from hem, imitative of clearing the throat.
ahimsa (n.) Look up ahimsa at Dictionary.com
1875, from Sanskrit ahimsa, from a "without" + himsa "injury."
ahistoric (adj.) Look up ahistoric at Dictionary.com
"not historical, lacking in historical background or justification," 1911, from a- (2) "not" + historic.
ahistorical (adj.) Look up ahistorical at Dictionary.com
"without reference to or regard for history," 1950, from a- (2) "not" + historical.
ahoy Look up ahoy at Dictionary.com
1751, from a + hoy, a nautical call used in hauling. The original form of the greeting seems to have been ho, the ship ahoy!
Ahura Mazda Look up Ahura Mazda at Dictionary.com
from Avestan ahura- "spirit, lord," from Indo-Iranian *asuras, from suffixed form of PIE root *ansu- "spirit" (see Asgard) + Avestan mazda- "wise," from PIE *mens-dhe- "to set the mind," from root *men- "to think" (see mind (n.)).
aid (n.) Look up aid at Dictionary.com
early 15c., "war-time tax," also "help, support, assistance," from Old French aide, earlier aiudha "aid, help, assistance" (9c.), from Late Latin adjuta, from fem. past participle of Latin adiuvare (past participle adiutus) "to give help to," from ad- "to" (see ad-) + iuvare "to help" (see adjutant). Meaning "thing by which assistance is given" is recorded from c.1600. Meaning "material help given by one country to another" is from 1940.
aid (v.) Look up aid at Dictionary.com
c.1400, "to assist, help," from Old French aidier "help, assistance," from Latin adiutare, frequentative of adiuvare (past participle adiutus) "give help to" (see adjutant). Related: Aided; aiding.
aide (n.) Look up aide at Dictionary.com
1777, short for aide-de-camp (1660s), which is French and means "camp assistant" (see aid (n.)).
AIDS (n.) Look up AIDS at Dictionary.com
1982, acronym formed from acquired immune deficiency syndrome. AIDS cocktail attested by 1997, the thing itself said to have been in use from 1995.
aiglet (n.) Look up aiglet at Dictionary.com
"metal tag of a lace," meant to make it easier to thread through the eyelet-holes, but later merely ornamental, mid-15c., from Middle French aiguillette, diminutive of aiguille "needle," from Late Latin acucula, itself a diminutive of Latin acus "needle" (see acuity). Compare Italian agucchia, Portuguese agulha, Spanish aguja "needle."
aikido (n.) Look up aikido at Dictionary.com
Japanese art of self-defense, 1936, literally "way of adapting the spirit," from Japanese ai "together" + ki "spirit" + do "way, art," from Chinese tao "way."
ail (v.) Look up ail at Dictionary.com
c.1300, from Old English eglan "to trouble, plague, afflict," from Proto-Germanic *azljaz (cognates: Old English egle "hideous, loathsome, troublesome, painful;" Gothic agls "shameful, disgraceful," agliþa "distress, affliction, hardship," us-agljan "to oppress, afflict"), from PIE *agh-lo-, suffixed form of root *agh- (1) "to be depressed, be afraid." Related: Ailed; ailing; ails.
It is remarkable, that this word is never used but with some indefinite term, or the word no thing; as What ails him? ... Thus we never say, a fever ails him. [Johnson]
ailanthus (n.) Look up ailanthus at Dictionary.com
"tree of heaven," 1807, Modern Latin, from Amboyna (Malay) ailanto "tree of the gods;" spelling altered by influence of Greek anthos "flower" (see anther).
aileron (n.) Look up aileron at Dictionary.com
1909, from French aileron, altered (by influence of aile "wing"), from French aleron "little wing," diminutive of Old French ele "wing" (12c.), from Latin ala "wing" (see aisle).
ailment (n.) Look up ailment at Dictionary.com
1706, from ail + -ment.
ailurophile (n.) Look up ailurophile at Dictionary.com
"cat lover," 1931, from Greek ailouros "cat," of unknown origin, + -phile.
ailurophobia (n.) Look up ailurophobia at Dictionary.com
"morbid fear of cats," 1905, from -phobia "fear" + ailouros "cat," of unknown origin. Folk etymology connects it with aiolos "quick-moving" + oura "tail." Related: Ailurophobe (1914).
aim (v.) Look up aim at Dictionary.com
early 14c., "to estimate, calculate," also "to intend," from Old French aesmer "value, rate; count, estimate," from Latin aestimare "appraise" (see estimation); current meaning apparently developed from "esteem," to "calculate," to "calculate with a view to action" (c.1400), then to "direct a missile, a blow, etc." (1570s). Related: Aimed; aiming.
aim (n.) Look up aim at Dictionary.com
early 14c., "target;" late 14c., "guess;" from aim (v.). Meaning "action of aiming" is from early 15c. (to take aim, originally make aim); that of "thing intended, purpose" is from 1620s.
aimless (adj.) Look up aimless at Dictionary.com
1620s, from aim (n.) + -less. Related: Aimlessly; aimlessness.
ain't Look up ain't at Dictionary.com
1706, originally a contraction of am not, and in proper use with that sense until it began to be used as a generic contraction for are not, is not, etc., in early 19c. Cockney dialect of London; popularized by representations of this in Dickens, etc., which led to the word being banished from correct English.
Ainu Look up Ainu at Dictionary.com
people native to northern Japan and far eastern Russia, 1819, from the Ainu self-designation, literally "man, human." Once considered to be Caucasian, based on their appearance; DNA testing has disproved this. Their language is an isolate with no known relatives.
air (v.) Look up air at Dictionary.com
"to expose to open air," 1520s, from air (n.1). Figurative sense of "to expose, make public" is from 1610s of objects, 1862 of opinions, grievances, etc. Meaning "to broadcast" (originally on radio) is from 1933. Related: Aired; airing.
air (n.1) Look up air at Dictionary.com
c.1300, "invisible gases that make up the atmosphere," from Old French air "atmosphere, breeze, weather" (12c.), from Latin aerem (nominative aer) "air, lower atmosphere, sky," from Greek aer (genitive aeros) "air" (related to aenai "to blow, breathe"), of unknown origin, possibly from a base *awer- and thus related to aeirein "to raise" and arteria "windpipe, artery" (see aorta) on notion of "lifting, that which rises." In Homer mostly "thick air, mist;" later "air" as one of the four elements.

Words for "air" in Indo-European languages tend to be associated with wind, brightness, sky. In English, air replaced native lyft, luft (see loft (n.)). To be in the air "in general awareness" is from 1875; up in the air "uncertain, doubtful" is from 1752. To build castles in the air is from 1590s (in 17c. English had airmonger "one preoccupied with visionary projects"). Broadcasting sense (as in on the air) first recorded 1927. To give (someone) the air "dismiss" is from 1900. Air pollution is attested by 1870.
air (n.2) Look up air at Dictionary.com
1590s, "manner, appearance" (as in an air of mystery); 1650s, "assumed manner, affected appearance" (especially in phrase put on airs, 1781), from French air "look, appearance, mien, bearing, tone" (Old French aire "reality, essence, nature, descent, extraction," 12c.; compare debonair), from Latin ager "place, field" (see acre) on notion of "place of origin."

But some French sources connect this Old French word with the source of air (n.1), and it also is possible these senses in English developed from or were influenced by air (n.1); compare sense development of atmosphere and Latin spiritus "breath, breeze," also "high spirit, pride," and the extended senses of anima.