air (n.3) Look up air at Dictionary.com
"melody, tune," 1580s, from Italian aria (see aria).
air conditioner (n.) Look up air conditioner at Dictionary.com
from air (n.1) + agent noun from condition; along with air-conditioning, first attested 1909, originally an industrial process; main modern use in residences and office buildings is from 1930s.
air force (n.) Look up air force at Dictionary.com
1917, from air (n.1) + force (n.); first attested with creation of the Royal Air Force. There was no United States Air Force until after World War II. The Air Corps was an arm of the U.S. Army. In 1942, the War Department reorganized it and renamed it Army Air Forces. The National Security Act of 1947 created the Department of the Air Force, headed by a Secretary of the Air Force, and the U.S.A.F.
air freshener (n.) Look up air freshener at Dictionary.com
1949, from air (n.1) + agent noun from freshen.
air mail (n.) Look up air mail at Dictionary.com
also air-mail, 1913, from air (n.1) + mail (n.1).
air raid (n.) Look up air raid at Dictionary.com
1914, from air (n.1) + raid (n.); originally in reference to British attacks Sept. 22, 1914, on Zeppelin bases at Cologne and Düsseldorf in World War I. The German word is Fliegerangriff "aviator-attack," and if Old English had survived into the 20th century our word instead might be fleogendeongrype.
One didn't dare to inhale for fear of breathing it in. It was the sound of eighteen hundred airplanes approaching Hamburg from the south at an unimaginable height. We had already experienced two hundred or even more air raids, among them some very heavy ones, but this was something completely new. And yet there was an immediate recognition: this was what everyone had been waiting for, what had hung for months like a shadow over everything we did, making us weary. It was the end. [Hans Erich Nossack, "Der Untergang," 1942]
airborne (adj.) Look up airborne at Dictionary.com
1640s, "carried through the air," from air (n.1) + borne. Of military units, from 1937.
aircraft (n.) Look up aircraft at Dictionary.com
1851, originally in reference to airships and balloons, from air (n.1) + craft (n.); a term from boating, as were many early aviation words. Of airplanes from 1907 and since 1930s exclusively of them. Aircraft carrier is attested from 1919 (H.M.S. Hermes, launched September 1919, was the first ship to be built from the hull up as an aircraft carrier).
Airedale Look up Airedale at Dictionary.com
type of terrier, 1880, named for Airedale, a district in West Riding, Yorkshire.
Name registered by Kennel Club (1886), for earlier Bingley (where first bred), or broken-haired terrier. [Weekley]
airfoil (n.) Look up airfoil at Dictionary.com
1922, U.S. form of aerofoil.
airhead (n.) Look up airhead at Dictionary.com
"empty-headed person," 1972, from air (n.1) + head (n.). Earlier as a term in mining (mid-19c.) and as a military term based on beachhead (1950).
airily (adv.) Look up airily at Dictionary.com
1766, from airy "with ostentatious air" (see air (n.2)) + -ly (2).
airing (n.) Look up airing at Dictionary.com
"action of exposing to air," c.1600, from present participle of air (v.). Meaning "display, public exposure is from 1870.
airlift (n.) Look up airlift at Dictionary.com
also air-lift, 1893 as a type of pumping device; 1945 in the sense "transportation of supplies by air," from air (n.1) + lift (n.). As a verb by 1949; popularized in reference to the response to the West Berlin blockade. Related: Air-lifted; air-lifting.
airline (n.) Look up airline at Dictionary.com
also air-line, 1813, "beeline, straight line between two points on the earth's surface" (as through the air, rather than over terrain; from 1853 and in later 19c. especially in reference to railways that ran directly between big cities in the U.S. instead of meandering from town to town in search of stock subscriptions as early railways typically did), from air (n.1) + line (n.). Meaning "public aircraft transportation company" is from 1914.
airplane (n.) Look up airplane at Dictionary.com
1907, from air (n.1) + plane (n.1); though the original references are British, the word caught on in American English, where it largely superseded earlier aeroplane (1873 in this sense and still common in British English). Aircraft "airplane" also is from 1907. Lord Byron, speculatively, used air-vessel (1822).
airplay (n.) Look up airplay at Dictionary.com
1950 in radio sense, from air (n.1) + play.
airport (n.) Look up airport at Dictionary.com
1919, from air (n.1) + port (n.1). First reference is to Bader Field, outside Atlantic City, New Jersey, U.S., which opened in 1910.
airship (n.) Look up airship at Dictionary.com
also air-ship, 1888, translating German Luftschiff "motor-driver dirigible;" see air (n.1) + ship (n.).
airtight (adj.) Look up airtight at Dictionary.com
also air-tight, "impervious to air," 1760, from air (n.1) + tight. Figurative sense of "incontrovertible" (of arguments, alabis, etc.) is from 1929.
airy (adj.) Look up airy at Dictionary.com
late 14c., "of the air, made of air," from air (n.1) + -y (2). Meaning "breezy" is attested from 1590s; that of "lively" is from 1640s. Sense of "vain, unsubstantial" is from 1580s. Disparaging airy-fairy is attested from 1920 (earlier in a sense of "delicate or light as a fairy," which is how Tennyson used it in 1830).
aisle (n.) Look up aisle at Dictionary.com
late 14c., ele, "lateral division of a church (usually separated by a row of pillars), from Old French ele "wing (of a bird or an army), side of a ship" (12c., Modern French aile), from Latin ala, related to axilla "wing, upper arm, armpit; wing of an army," from PIE *aks- "axis" (see axis), via a suffixed form *aks-la-. The root meaning in "turning" connects it with axle and axis.

Confused from 15c. with unrelated ile "island" (perhaps from notion of a "detached" part of a church), and so it took an -s- when isle did, c.1700; by 1750 it had acquired an a-, on the model of French cognate aile. The word also was confused with alley, which gave it the sense of "passage between rows of pews or seats" (1731), which was thence extended to railway cars, theaters, etc.
ajar Look up ajar at Dictionary.com
1718, perhaps from Scottish dialectal a char "slightly open," earlier on char (early 16c.), from Middle English char, from Old English cier "a turn."
Ajax Look up Ajax at Dictionary.com
name of two Greek heroes in the Trojan War (Great Ajax, son of Telamon, and Little Ajax, son of Oileus), Latin, from Greek Aias, perhaps originally the name of an earth-god, from aia "earth." The Elizabethans punned on the name as a jakes "a privy."
akimbo Look up akimbo at Dictionary.com
c.1400, in kenebowe, of unknown origin, perhaps from Middle English phrase in keen bow "at a sharp angle," or from a Scandinavian word akin to Icelandic kengboginn "bow-bent," but this seems not to have been used in this exact sense. Many languages use a teapot metaphor for this, such as French faire le pot a deux anses "to play the pot with two handles."
akin (adj.) Look up akin at Dictionary.com
1550s, from phrase of kin; see kin.
Akkadian Look up Akkadian at Dictionary.com
1855, from Akkad (Sumerian Agde, Biblical Acca), name of city founded by Sargon I in northern Babylonia, of unknown origin; applied by modern scholars to the east Semitic language spoken there (c.2300-2100 B.C.E.) and preserved in cuneiform inscriptions.
al dente Look up al dente at Dictionary.com
1935, Italian, literally "to the tooth," from Latin dent (see tooth).
al fresco Look up al fresco at Dictionary.com
1753, Italian, literally "in the fresh (air)." Italian al represents a contraction of words from Latin ad "to" (see ad-) + ille "that." Alfresco also meant "painted on plaster that was still fresh or moist" (1764; see fresco).
al Qaeda Look up al Qaeda at Dictionary.com
alternative Latin alphabet transliteration of Arabic al Qaida (q.v.).
al Qaida Look up al Qaida at Dictionary.com
also Al-Qaeda; name of a loosely structured jihadist movement founded c.1989 by Osama bin Laden; from Arabic, literally "the base." A common Arabic term among Muslim radicals from the wider Islamic world who came to Afghanistan in 1980s and fought alongside local rebels against the Soviets, and who regarded themselves and their struggle not merely in Afghan terms but as the "base" or foundation of a wider jihad and revival in Islam. Used by Bin Laden's mentor, Abdallah Azzam (1941-1989), who referred to the "vanguard" which "constitutes the strong foundation [al-qaida al-sulbah] for the expected society." In U.S., the term first turns up in a CIA report in 1996.
Every Muslim, from the moment they realise the distinction in their hearts, hates Americans, hates Jews, and hates Christians. This is a part of our belief and our religion. For as long as I can remember, I have felt tormented and at war, and have felt hatred and animosity for Americans. [Osama bin Laden, interview aired on Al-Jazeera, December 1998]
Alabama Look up Alabama at Dictionary.com
created and named as a U.S. territory 1817 by a division of Mississippi Territory; ultimately named for one of the native peoples who lived there, who speak Muskogean. Their name probably is from a Choctaw term meaning "plant-cutters." Related: Alabamian.
alabaster (n.) Look up alabaster at Dictionary.com
translucent whitish kind of gypsum used for vases, ornaments, and busts, late 14c., from Old French alabastre (12c., Modern French albâtre), from Latin alabaster "colored rock used to make boxes and vessels for unguents," from Greek alabastros (earlier albatos) "vase for perfumes," perhaps from Egyptian 'a-labaste "vessel of the goddess Bast." Used figuratively for whiteness and smoothness from 1570s. "The spelling in 16-17th c. is almost always alablaster ..." [OED].
alabastrine (adj.) Look up alabastrine at Dictionary.com
1590s, from Medieval Latin alabastrinus, from alabaster (see alabaster).
alack Look up alack at Dictionary.com
late 15c., from ah, lack, from lack in Middle English sense of "loss, failure, reproach, shame." Originally an expression of dissatisfaction, later of regret or unpleasant surprise.
alacrity (n.) Look up alacrity at Dictionary.com
mid-15c., from Latin alacritatem (nominative alacritas) "liveliness, ardor, eagerness," from alacer (genitive alacris) "cheerful, brisk, lively;" of uncertain origin, perhaps cognate with Gothic aljan "zeal," Old English ellen "courage, zeal, strength," Old High German ellian.
Aladdin Look up Aladdin at Dictionary.com
name of a hero in stories from the Arabian Nights, from Arabic Ala' al Din, literally "nobility of faith."
Alamo Look up Alamo at Dictionary.com
nickname of Franciscan Mission San Antonio de Valeroin (begun 1718, dissolved 1793) in San Antonio, Texas; American Spanish, literally "poplar" (in New Spain, also "cottonwood"), from alno "the black poplar," from Latin alnus "alder" (see alder).

Perhaps so called in reference to trees growing nearby (compare Alamogordo, New Mexico, literally "big poplar," and Spanish alameda "a public walk with a row of trees on each side"); but the popular name seems to date from the period 1803-13, when the old mission was the base for a Spanish cavalry company from the Mexican town of Alamo de Parras in Nueva Vizcaya.
Alan Look up Alan at Dictionary.com
masc. proper name, 1066, from Old Breton Alan, name of a popular Welsh and Breton saint; brought to England by the large contingent of Bretons who fought alongside William the Conqueror.
alar (adj.) Look up alar at Dictionary.com
"wing-like," c.1840; "of or pertaining to wings," 1847, from Latin alaris, from ala "wing, armpit, wing of an army" (source of Spanish ala, French aile), from *axla, originally "joint of the wing or arm;" from PIE *aks- (see axis).
Alaric Look up Alaric at Dictionary.com
Visigothic masc. proper name, literally "all-ruler," from Proto-Germanic *ala- "all" (see all) + *rikja "rule" (see rich).
alarm (n.) Look up alarm at Dictionary.com
early 14c., from Old French alarme (14c.), from Italian all'arme "to arms!" (literally "to the arms"). An interjection that came to be used as the word for the call or warning (compare alert). Extended 16c. to "any sound to warn of danger or to arouse." Weakened sense of "apprehension, unease" is from 1833. Variant alarum is due to the rolling -r- in the vocalized form. Sometimes in early years anglicized as all-arm. Alarm clock is attested from 1690s (as A Larum clock).
alarm (v.) Look up alarm at Dictionary.com
1580s, from alarm (n.). Related: Alarmed; alarming.
alarmed (adj.) Look up alarmed at Dictionary.com
"disturbed by prospects of peril," 1640s, past participle adjective from alarm (v.).
alarmingly (adv.) Look up alarmingly at Dictionary.com
1787, from alarming, present participle adjective from alarm (v.), + -ly (2).
alarmist (n.) Look up alarmist at Dictionary.com
"one addicted to sounding alarms," 1793, from alarm (n.) + -ist.
alarum (n.) Look up alarum at Dictionary.com
obsolete and poetic spelling of alarm (n.).
alas Look up alas at Dictionary.com
mid-13c., from Old French ha, las (later French hélas), from ha "ah" + las "unfortunate," originally "tired, weary," from Latin lassus "weary" (see late). At first an expression of weariness rather than woe.
Alaska Look up Alaska at Dictionary.com
name first applied 18c. by Russian explorers, from Aleut alaxsxaq, literally "the object toward which the action of the sea is directed" [Bright]. Baked Alaska attested by 1896, so called either for its whiteness or from being cold inside.
Alastor Look up Alastor at Dictionary.com
in Greek tradition, son of Neleus, brother of Nestor, slain by Herakles. The name is perhaps literally "not to forget," from privative prefix a- "not" + root of lathein "to forget" (see Lethe), hence its use figuratively in sense of "an avenging spirit." Or else it might be connected with alaomai "to wander, roam," figuratively "to be distraught."