Online Etymology Dictionary

are (n.): square unit of 10 meters on each side, 1819, from French, formed 1795 by decree of the French National Convention, from Latin area "vacant piece of ground" (see area).
area (n.): 1530s, "vacant piece of ground," from Latin area "level ground, open space," used of building sites, playgrounds, threshing floors, etc.; which is of uncertain origin. Perhaps related to arere "to become dry," on notion of a burned clearing or dry, bare space. The generic sense of "amount of surface (whether open or not) contained within any set of limits" is from 1845. Area code in North American telephone systems is attested from 1959.
areal (adj.): 1670s, from Latin arealis, from area (see area).
aren't: 1794, contraction of are not, originally written are'n't and generally so into early 19c.
If "ain't I?" is objected to, surely "aren't I?" is very much worse. [Lady Grove, "The Social Fetich," 1907]
arena (n.): 1620s, "place of combat," from Latin harena "place of combat," originally "sand, sandy place," perhaps from Etruscan. The central stages of Roman amphitheaters were strewn with sand to soak up the blood.
areola (n.): "colored circle around a nipple," 1706, from Latin areola, literally "small area," diminutive of area (see area). Introduced in this sense 1605 by Swiss anatomist and botanist Caspar Bauhin (1560-1624).
areolas (n.): nativized plural of areola (q.v.), which has its proper plural in areolae (see -ae).
Areopagite (n.): "member of the Areopagus court," late 14c.; see Areopagus + -ite (1). See Acts xvii:34.
Areopagus: 1640s, Greek, Areios pagos "the hill of Ares," west of the Acropolis in Athens, where the highest judicial court sat; second element from pagos "rocky hill." Sense extended to "any important tribunal."
Ares: Greek god of war, identified by Romans with their Mars; literally "injurer, destroyer," from are "bane, ruin," perhaps cognate with Sanskrit irasya "ill-will" (see ire).
arete (n.1): "sharp crest of a mountain," 1862, from Swiss French arête, from Latin arista "ear of grain, the top of an ear," which probably is of Etruscan origin. The figure is of something jagged.
arete (n.2): important concept in Greek philosophy, "virtue, excellence," especially of manly qualities; literally "that which is good." The comparative form is areion, the superlative is aristos (compare aristocracy).
argent (n.): c. 1300, "quicksilver, the metal mercury," from Old French argent (11c.), from Latin argentum "silver, silver work, white money," from PIE *arg-ent- (source also of Avestan erezata-, Old Persian ardata-, Armenian arcat, Old Irish argat, Breton arc'hant "silver"), from root *arg- "to shine; white," thus "the shining or white metal, silver" (source also of Greek argos "white," arguron "silver;" Sanskrit arjuna- "white, shining," rajata- "silver," Hittite harki- "white"). Meaning "silver, silver coin" is early 15c. in English; the adjective sense "silver-colored," late 15c.
Argentina: South American nation, from Latin argentinus "of silver" (see argent); a Latinized form of (Rio) de la Plata, from Spanish plata "silver."
argentine (adj.): "silver-colored," mid-15c., from Latin argentinus "of silver," from argentum (see argent).
Argentine (adj.): "of or from Argentina," 1830 (from 1829 as a noun); Argentinian is from 1845 as a noun; 1858 as an adjective.
Argive (adj.): "of Argos," hence, especially in Homeric usage, "the Greeks," as a byword for Achaean (he describes Agamemnon as king of Argos), 1520s, from Latin Argivus, from Greek Argeios "of Argos."
argle (v.): 1580s "to argue obstinately," from argue, perhaps by influence of haggle. Reduplicated form argle-bargle (sometimes argy-bargy) "wrangling" is attested from 1872.
Argo: name of the ship in which Jason and his companions sought the Fleece in Colchis, in Greek, literally "The Swift," from argos "swift" (adj.), an epithet, literally "shining, bright" (see argent; compare also Sanskrit cognate rjrah "shining, glowing, bright," also "swift"), "because all swift motion causes a kind of glancing or flickering light" [Liddell & Scott].
argon (n.): chemical element, 1894, Modern Latin, from Greek argon, neuter of argos "lazy, idle, not working the ground, living without labor," from a- "without" (see a- (3)) + ergon "work" (see organ). So called by its discoverers, Baron Rayleigh and Sir William Ramsay, for its inert qualities.
Argonaut (n.): "sailor of the Argo," 1580s (implied in argonautic), from Argo + Greek nautes "sailor" (see naval). Adventurers in the California Gold Rush of 1848 were called argonauts (because they sought the golden fleece) by those who stayed home.
argosy (n.): 1570s, from Italian (nave) Ragusea "(vessel) of Ragusa," maritime city on the Dalmatian coast of the Adriatic (modern Dubrovnik in Croatia). Their large merchant ships brought rich Eastern goods to 16c. England. The city name sometimes was Aragouse or Arragosa in 16c. English.
argot (n.): 1860, from French argot (17c.) "the jargon of Paris rogues and thieves," earlier "the company of beggars," from Middle French argot, "group of beggars," origin unknown. Gamillscheg suggests a connection to Old French argoter "to cut off the stubs left in pruning," with a connecting sense of "to get a grip on." The best English equivalent is perhaps cant. The German equivalent is Rotwelsch, literally "Red Welsh," but the first element may be connected with Middle High German rot "beggar." Earlier in English was pedlar's French (1520s) "language of thieves and vagabonds."
arguable (adj.): 1610s, from argue + -able.
arguably (adv.): "as may be shown by argument," 1890, from arguable + -ly (2).
argue (v.): c. 1300, "to make reasoned statements to prove or refute a proposition," from Old French arguer "maintain an opinion or view; harry, reproach, accuse, blame" (12c.), from Latin argutare "to prattle, prate," frequentative of arguere "make clear, make known, prove, declare, demonstrate," from PIE *argu-yo-, from root *arg- "to shine, be white, bright, clear" (see argent). Meaning "to oppose, dispute" is from late 14c. Related: Argued; arguing.
arguendo: "in the course of argument," 1817, courtroom Latin, from Medieval Latin ablative of arguendum, gerundive of arguere "to argue" (see argue).
arguer (n.): late 14c., agent noun from argue (v.).
argufy (v.): 1751, colloquial, from argue + -fy.
argument (n.): early 14c., "statements and reasoning in support of a proposition," from Old French arguement "reasoning, opinion; accusation, charge" (13c.), from Latin argumentum "evidence, ground, support, proof; a logical argument," from arguere "to argue" (see argue). Sense passed through "subject of contention" to "a quarrel," a sense formerly attached to argumentation.
argumentation (n.): mid-15c., "presentation of formal arguments," from Old French argumentacion (14c.), from Latin argumentationem (nominative argumentatio) "the bringing forth of a proof," noun of action from past participle stem of argumentari (see argue). Meaning "debate, wrangling, argument back and forth" is from 1530s.
argumentative (adj.): mid-15c., "pertaining to arguments," from Old French argumentatif or directly from Latin argumentat-, past participle stem of argumentari (see argue) + -ive. Meaning "fond of arguing" is recorded from 1660s. Related: Argumentatively; argumentativeness.
Argus: hundred-eyed giant of Greek mythology, late 14c., from Latin, from Greek Argos, literally "the bright one," from argos "shining, bright" (see argent). His epithet was Panoptes "all-eyes." After his death, Hera transferred his eyes to the peacock's tail. Used in figurative sense of "very vigilant person."
Argyle (n.): "diamond-shaped pattern of two or more colors in fabric," said to be so called from similarity to tartans worn by Campbell clan of Argyll, Scotland. The place name is literally "land of the Gaels," from Old Irish airer "country." Argyle socks is from 1935.
aria (n.): from Italian aria, literally "air" (see air (n.1)).
Arian (adj.): 1530s, pertaining to the doctrines of Arius, priest in Alexandria early 4c., who posed the question of Christ's nature in terms which appeared to debase the Savior's relation to God (denial of consubstantiation). Besides taking an abstract view of Christ's nature, he reaffirmed man's capacity for perfection. The dissention was widespread and split the Church for about a century during a crucial time.
Arianism (n.): c. 1600, from Arian + -ism.
arid (adj.): 1650s, "dry, parched," from French aride (15c.) or directly from Latin aridus "dry, arid, parched," from arere "to be dry," from PIE root *as- "to burn, glow" (see ash (n.1)). Figurative sense of "uninteresting" is from 1827. Related: Aridly.
aridity (n.): 1590s, from Middle French aridité or directly from Latin ariditatem (nominative ariditas) "dryness," from aridus (see arid). The Latin word was used figuratively of unadorned styles as well as stingy men.
ariel: 1382, in the Wyclif Bible, a word taken untranslated from the Vulgate, from Greek ariel (Sept.), from Hebrew ariel; in later Bibles, translated as "altar."
(Gesenius would here translate "fire-hearth of God," after Arab. arr; elsewhere in O.T. the same word occurs as a man's name, and appellation of Jerusalem, where it is taken as = "lion of God.") Ariel in T. Heywood and Milton is the name of an angel, in Shakespeare of "an Ayrie spirit"; in Astron. of one of the satellites of Uranus. [OED]
As the name of a species of gazelle found in the Middle East, 1832, from Arabic aryil, variant of ayyil "stag."
Aries: zodiac constellation usually identified as "the Ram," late Old English, from Latin aires "ram" (related to arietare "to butt"), from a PIE root meaning "spring, jump" (source also of Lithuanian erytis, Old Church Slavonic jarici, Armenian oroj "lamb;" Greek eriphos, Old Irish heirp "kid"). Meaning "person born under the sign of Aries" is from 1894; they also have been called Arian (1917).
aright (adv.): "in a correct way," Old English ariht, from a- (1) "of" + right (adj.).
aril (n.): "accessory covering of seeds," 1794, from Modern Latin arillus, from Medieval Latin arilli, Spanish arillos "dried grapes, raisins."
Arimasp (n.): Latin Arimaspi (plural), from Greek Arimaspoi, mythical race of one-eyed people in Northern Europe believed in antiquity to have carried off a hoard of gold which was under guardianship of griffins. The name is said to be Scythian for "one-eyed." Related: Arimaspian.
arioso: "melodious, in a melodious way," 1742, from Italian aria "melody" (see aria).
arise (v.): Old English arisan "to get up, rise; spring from, originate; spring up, ascend" (cognate with Old Saxon arisan, Gothic urreisan), from a- (1) "of" + rise (v.). Mostly replaced by rise except in reference to circumstances. Related: Arising; arose; arisen.
arisen: past participle of arise (q.v.).
arising (n.): verbal noun from arise (v.). Replaced in most senses by rising.
aristarchy (n.): "government by the best men," from Greek aristarkhia, from aristos "best" (see aristocracy) + -arkhia (see -archy).
aristocracy (n.): 1560s, from Middle French aristocracie (Modern French aristocratie), from Late Latin aristocratia, from Greek aristokratia "government or rule of the best," from aristos "best" (originally "most fitting," from PIE *ar-isto-, superlative form of *ar- "to fit together;" see arm (n.1)) + kratos "rule, power" (see -cracy).

At first in a literal sense of "government by those who are the best citizens;" meaning "rule by a privileged class" (best-born or best-favored by fortune) is from 1570s and became paramount 17c. Hence, the meaning "patrician order" (1650s). In early use contrasted with monarchy; after French and American revolutions, with democracy.