Online Etymology Dictionary

garlic (n.): Old English garleac (Mercian), garlec (W. Saxon) "garlic," from gar "spear" (in reference to the clove), see gar + leac "leek" (see leek).
garlicky (adj.): 1775, from garlic + -y (2).
garment (n.): c.1400, variant of garnement (early 14c.), from Old French garnement "garment, attire, clothes," from garnir "fit out, provide, adorn" (see garnish).
garner (v.): late 15c., from garner (n.). Related: Garnered; garnering.
garner (n.): late 12c., gerner, from Old French gernier, metathesized variant of grenier "storehouse, loft for grain," from Latin granarium "a store-house" (see granary).
garnet (n.): early 14c., metathesized from Old French grenat "garnet," originally an adjective, "of a dark red color," from Medieval Latin granatum, originally an adjective, "of dark red color," perhaps abstracted from pomegranate (q.v.), from the stone's resemblance either to the shape of the seeds or the color of the pulp. But perhaps the word is from Medieval Latin granum "grain," in its sense of "cochineal, red dye."
garnish (v.): late 14c., from Old French garniss-, present participle stem of garnir "provide, furnish; fortify, reinforce," from a Germanic stem related to Proto-Germanic *warnejan "be cautious, guard, provide for" (cf. Old High German warnon "to take heed," Old English warnian "to take warning, beware;" see warn). Sense evolution is from "arm oneself" to "fit out" to "embellish," which was the earliest meaning in English, though the others also were used in Middle English. Culinary sense of "to decorate a dish for the table" predominated after c.1700. Older meaning survives in legal sense of "warning of attachment of funds" (1570s). Related: Garnished; garnishing.
garnish (n.): late 14c., "set of tableware" (probably a dozen; usually pewter), from garnish (v.). Sense of "embellishments to food" is from 1670s.
garnishee (n.): 1620s, from garnish (v.) + -ee.
garnishment (n.): 1520s, from garnish + -ment.
garret (n.): c.1300, "turret, small tower on the roof of a house or castle," from Old French garite "watchtower, place of refuge," from garir "defend, preserve," from a Germanic source (cf. Gothic warjan "forbid," Old High German warjan "to defend"), from Proto-Germanic *warjanan, from PIE root *wer- "to cover" (see warrant). Meaning "room on uppermost floor of a house" is from early 14c. See attic. As the typical wretched abode of a poor poet, by mid-18c.
Garrett: surname, from mid-13c., from Gerald or Gerard, with loss of consonant.
garrison (v.): 1560s, from garrison (n.). Related: Garrisoned; garrisoning.
garrison (n.): c.1300, "store, treasure," from Old French garison "defense" (Modern French guérison "cure, recovery, healing") from garir "defend" (see garret). Meaning "fortified stronghold" is from early 15c.; that of "body of troops in a fortress" is from mid-15c., a sense taken over from Middle English garnison "body of armed men" (late 14c.), from Old French garnison "provision, munitions," from garnir "to furnish, provide."
garrot (n.): kind of duck, from French garrot, of unknown origin.
garrote (v.): "to execute with a garrote," 1851, from garrote (n.); sense of "choke and then rob" is from 1852. Related: Garotted; garotting.
garrote (n.): also garrotte, 1620s, "Spanish method of capital punishment by strangulation," from Spanish garrote "stick for twisting cord," of unknown origin, perhaps from Old French guaroc "club, stick, rod, shaft of a crossbow," probably ultimately Celtic, but possibly from Frankish *wrokkan "to twist" (cf. Middle Dutch wroken "to twist").
I have no hesitation in pronouncing death by the garrot, at once the most manly, and the least offensive to the eye. [Major John Richardson, "British Legion," 1837]
garrulity (n.): 1580s, from Middle French garrulité, from Latin garrulitatem (nominative garrulitas) "chattering, loquacity," from garrulus (see garrulous).
garrulous (adj.): 1610s, from Latin garrulus "talkative," from garrire "to chatter," from PIE root *gar- "to call, cry," of imitative origin (cf. Greek gerys "voice, sound," Ossetic zar "song," Welsh garm, Old Irish gairm "noise, cry"). Related: Garrulously; garrulousness.
garter (n.): early 14c., from Old North French gartier "band just above or below the knee" (Old French jartier, 14c., Modern French jarretière), from garet "bend of the knee," perhaps from Gaulish (cf. Welsh garr "leg"). Garter as the highest order of knighthood (mid-14c.), according to Froissart was established c.1344 by Edward III, though the usual story of how it came about is late (1614) and perhaps apocryphal. The verb is mid-15c., from the noun. Garter snake (U.S.) so called from resemblance to a ribbon. Garter belt first noticed 1913.
garth (n.): "small piece of enclosed ground," northern and western English dialect word, mid-14c., from Old Norse garðr "yard, courtyard, fence," cognate of Old English geard (see yard (n.1)).
Gary: masc. proper name, also a surname, from Norman form of Old Norse geiri, Old Danish geri "spear" (see gar).
gas (n.): 1650s, from Dutch gas, probably from Greek khaos "empty space" (see chaos). The sound of Dutch "g" is roughly equivalent to that of Greek "kh." First used by Flemish chemist J.B. van Helmont (1577-1644), probably influenced by Paracelsus, who used khaos in an occult sense of "proper elements of spirits" or "ultra-rarified water," which was van Helmont's definition of gas.

Modern scientific sense began 1779, with later specialization to "combustible mix of vapors" (1794, originally coal gas); "anesthetic" (1894, originally nitrous oxide); and "poison gas" (1900). Meaning "intestinal vapors" is from 1882. "The success of this artificial word is unique" [Weekley]. Slang sense of "empty talk" is from 1847; slang meaning "something exciting or excellent" first attested 1953, from earlier hepster slang gasser in the same sense (1944). Gas also meant "fun, a joke" in Anglo-Irish and was used so by Joyce (1914). As short for gasoline, it is American English, first recorded 1905.
gas (v.): 1886, "to supply with gas," from gas (n.). Sense of "poison with gas" is from 1889 as an accidental thing, from 1915 as a military attack. Related: Gassed; gassing.
gas-guzzler (n.): car with low fuel-efficiency, 1973, American English, from gas (short for gasoline) + guzzler.
Gascon: "native of Gascony," late 14c., from Middle French Gascon, from Vulgar Latin *Wasco, from Latin Vasco, singular of Vascones, the name of the ancient inhabitants of the Pyrénées (see Basque). Proverbially a boastful people, hence gasconade (n.), "bragging talk."
gasconade: 1709 (n.); 1727 (v.), from French gasconade (see Gascon + -ade); from gasconner (16c.) "to boast, brag," literally "to talk like a Gascon."
gaselier (n.): "gas-burning chandelier," 1849, from gas (n.) + chandelier.
gaseous (adj.): 1799, from gas (n.) + -ous.
gash (v.): 1560s, alteration of garsen (late 14c.), from Old North French garser "to cut, slash" (see gash (n.)). Related: Gashed; gashing.
gash (n.): 1540s, from Middle English garce (early 13c.), from Old North French garser "to scarify, cut, slash" (Old French *garse), apparently from Vulgar Latin *charassare, from Greek kharassein "engrave," from PIE *gher- "to scrape, scratch" (cf. character). Loss of -r- is characteristic (see ass (2)). Slang use for "vulva" dates to mid-1700s.
gashouse (n.): 1880 as a power-generating station, from gas (n.) + house (n.). By 1926, emblematic of a run-down district of a U.S. city, a typical abode of gangsters.
gasket (n.): 1620s, caskette "small rope or plaited coil used to secure a furled sail," of uncertain origin, perhaps from French garcette "little girl, maidservant," diminutive of Old French garce (13c.) "young woman, young girl; whore, harlot, concubine," fem. of garçon (see garcon). Sense of "packing (originally of braided hemp) to seal metal joints" first recorded 1829.
gasohol (n.): gasoline and ethanol mixture, 1975, from gasoline + (ethyl) alcohol.
gasoline (n.): 1864 (alternative spelling gasolene is from 1865), from gas + -ol (probably here representing Latin oleum "oil") + chemical suffix -ine (2). Shortened form gas was in common use in U.S. by 1897. Gas station as a fuel filling station for automobiles recorded by 1924.
gasometer (n.): 1790, from gas + -meter. Related: Gasometric.
gasp (n.): 1570s, from gasp (v.).
gasp (v.): late 14c., gaspen, of uncertain origin, perhaps from Old Norse geispa "to yawn," or its Danish derivative gispe "gasp," which probably are related to Old Norse gapa (see gape). Related: Gasped; gasping.
gassy (adj.): 1757, from gas + -y (2).
gast (adj.): “animal which does not produce in season,” 1729, an East Anglian dialect word, perhaps from Middle Dutch gast “barren soil.”
gastrectomy (n.): 1886, from gastro- + -ectomy.
gastric (adj.): 1650s, with -ic + Greek gaster (genitive gastros) "stomach," by dissimilation from *graster, literally "eater, devourer," from gran "to gnaw, eat," from PIE root *gras- "to devour" (cf. Greek grastis "green fodder," Latin gramen "fodder, grass," Old English cærse "cress").
gastritis (n.): 1806, medical Latin, from gastro- + -itis. Coined by French pathologist François-Boissier de la Croix de Sauvages (1706-1767).
gastro-: scientific word-forming element meaning "stomach," before vowels gastr-, from Greek gastro-, comb. form of gaster (genitive gastros) "belly, paunch" (see gastric).
gastrocnemius (n.): 1670s, from Latinized form of Greek gastroknemia "calf of the leg," from gaster "belly" (see gastric) + kneme "leg." So called for its form. Related: Gastrocnemical.
gastroenteritis (n.): 1820s, from gastro- + enteritis.
gastroenterology (n.): 1904, from gastro- + enterology. Related: Gastroenterologist.
gastrointestinal (adj.): 1831, from gastro- + intestinal.
gastrolator (n.): "belly-worshipper," 1690s, from gastro- + Greek -latros "serving" (see -latry).
gastrology (n.): "cooking, good eating," 1810, from gastro- "stomach" + -logy.