Online Etymology Dictionary

-gate: suffix attached to anything to indicate "scandal involving," 1973, abstracted from Watergate, Washington, D.C., building complex, home of the National Headquarters of the Democratic Party when it was burglarized June 17, 1972.
-gram: suffix from telegram (1857), first abstracted 1979 (in Gorillagram, a proprietary name in U.S.), and put to wide use in forming new words, such as stripagram (1981). The construction violates Gk. grammar, as an adv. could not properly form part of a compound noun.
G-man: "FBI agent," 1930, shortening of government man; used earlier in an Irish context (1917), but the abbreviation is perhaps the same one.
G-string: 1878, geestring, "loincloth worn by American Indian," originally the string that holds it up, etymology unknown. The spelling with G (1891) is perhaps from influence of violin string tuned to a G (in this sense G string is first recorded 1831). First used of women's attire 1936, with reference to strip-teasers.
G.I.: 1936 (adj.), Amer.Eng., apparently an abbreviation of Government Issue, applied to anything associated with servicemen. Transferred sense to "soldiers" during World War II (first recorded 1943) is from the jocular notion that the men themselves were manufactured by the government. An earlier G.I. was an abbreviation of Galvanized Iron in G.I. can, a type of metal trash can, the term being picked up by U.S. soldiers in World War I as slang for a similar-looking type of German artillery shells. This use is attested from 1928, but it is highly unlikely that this came to mean "soldier." I probably get more e-mail about this entry than any other. No two sources I have agree on the etymology, but none backs the widespread notion that it stands for *General Infantry.
gab: c.1200, via Scottish and northern England dialect, from O.N. gabba "to mock," or O.Fr. gabber "mock, boast," both probably ultimately imitative. Gabby first attested 1719; gabfest "session of conversation" is 1897 Amer.Eng. slang. Gift of the gab "talent for speaking" is from 1681.
gabardine: "fine worsted cloth," 1904, earlier gaberdine "long, coarse outer garment" (1520), from Sp. gabardina, from M.Fr. galverdine, which is perhaps from M.H.G. wallevart "pilgrimage," in the sense of "pilgrim's cloak." The Sp. form perhaps infl. by gabán "overcoat" and tabardina "coarse coat."
gabble: 1577, frequentative of gab (q.v.).
gabbro: "type of igneous rock," 1837, from It. (Tuscan), from L. glaber "bare, smooth, bald."
gable: 1338, from O.Fr. gable, from O.N. gafl (in north of England, directly from O.N.), probably from a P.Gmc. root meaning "fork" (cf. O.E. gafol, geafel "fork," M.H.G. gabel "pitchfork"), from PIE *ghebhel (cf. O.Ir. gabul "forked twig"). So called from the Y-shaped timber supports of the roof at gable ends.
Gabriel: name of an archangel in O.T., from Heb. Gabhri el, lit. "man of God," from gebher "man" + El "God." First element is from base of verb gabhar "was strong" (cf. Arabic jabr "strong, young man;" jabbar "tyrant").
gad (v.): "to rove about," 1460, perhaps a back-formation of O.E. gædeling "wandering," or associated with gad (n.) "a goad for driving cattle" (see gadfly). Gadabout (n.) is 1837, from earlier noun gadder about (1568).
gadfly (n.): 1620s, "fly which bites cattle," probably from gad "goad, metal rod" (early 13c.), here in the sense of "stinger," from O.N. gaddr "spike, nail," from P.Gmc. *gadaz "pointed stick;" but sense is entangled with gad (v.) and an early meaning of gadfly was also "someone who likes to go about, often stopping here and there." Sense of "one who irritates another" is from 1640s (equivalent of L. oestrus).
gadget: 1886, gadjet (but said to date back to 1850s), sailors' slang word for any small mechanical thing or part of a ship for which they lacked, or forgot, a name; perhaps from Fr. gâchette "catchpiece of a mechanism," dim. of gâche "staple of a lock."
gadzooks: 1694, from some exclamation, possibly God's hooks (nails of the cross) or even God's hocks. The use of Gad for God (cf. egad) is first attested 1598. Among other similar phraseological combinations (all from 17c.) were gadsbobs, gadslid, and gadsniggers.
Gaelic: 1774, earlier Gathelik (1596), from Gael (Scottish Gaidheal), from O.Ir. Goidhel, the original form of the word. The native name in both Ireland and Scotland, Gael was first used in Eng. exclusively of Scottish Highlanders (1596).
gaffe: "blunder," 1909, from Fr. gaffe "clumsy remark," originally "boat hook," from O.Fr. gaffe, from O.Prov. gaf, probably from W.Goth. *gafa "hook," from P.Gmc. *gafa. Sense connection is obscure. The gaff was also used to land big fish. Or it may derive from Brit. slang gaff "to cheat, trick" (1893); or gaff "criticism" (1896), from Scot. dial. sense of "loud, rude talk," which ultimately may be from O.E. gaf-spræc "blasphemous or ribald speech."
gaffer: 1589, "elderly rustic," apparently a contraction of godfather; originally "old man," it was applied from 1841 to foremen and supervisors, which sense carried over 20c. to "electrician in charge of lighting on a film set."
gag (v.): c.1440, "to choke, strangle," possibly imitative or influenced by O.N. gaghals "with head thrown back." The sense of "stop a person's mouth" is first attested 1509. The noun is 1553, from the verb.
gag (n.): "joke," 1823, probably related to theatrical sense of "matter interpolated in a written piece by the actor" (1847), or from slang verbal sense of "to deceive, take in with talk" (1777), both on notion of "stuff, fill" (see gag (v.)).
gaga: "crazy, silly," 1905, probably from Fr. gaga "senile, foolish."
gaggle: c.1470, gagyll, with ref. to both geese and women. Barnhardt says possibly from O.N. gagl "goose;" OED calls it "one of the many artificial terms invented in the 15th c. as distinctive collectives referring to particular animals or classes of persons." Possibly of imitative origin (cf. Du. gagelen "to chatter;" M.E. gaggle "to cackle," used of geese, attested from 1399).
Gaia: "Earth as a goddess," from Gk. Gaia, personification of gaia "earth," a collateral form of ge (Dorian ga) "earth," of unknown origin. The Roman equivalent goddess of the earth was Tellus (see tellurian), sometimes used in Eng. poetically or rhetorically for "Earth personified" or "the Earth as a planet."
gaiety: 1647, from Fr. gaieté, from gai "gay" (see gay).
gain: 1496 (n.), 1530 (v.), from M.Fr. gain, from O.Fr. gaaigne, from gaaignier "to gain," also "cultivate land," from Frank. *waidanjan "hunt, forage," also "graze, pasture," from P.Gmc. *wartho "hunting ground" (cf. Ger. weide "pasture, pasturage," O.N. veiðr "hunting"), from PIE *wei "to strive after." The original O.Fr. sense enfolded the notions of "profit from agriculture" and "booty, prey."
gainsay: "to contradict," c.1300, lit. "say against," from O.E. gegn- "against" + say. "Solitary survival of a once common prefix" [Weekley], which was used to form such now-obsolete compounds as gain-taking "taking back again," gainclap "a counterstroke," gainbuy "redeem," and gainstand "to oppose."
gait: c.1200, gate "a going or walking, departure, journey," earlier "way, road, path," from O.N. gata "way, road, path." Meaning "manner of walking" is from 1509. Modern spelling developed before 1750, originally in Scottish.
gaiter: "leather cover for the ankle," 1775, perhaps from Fr. guêtre "belonging to peasant attire," from M.Fr. *guestre, probably from Frank. *wrist "instep," from P.Gmc. *wirstiz from *wrig-, *wreik- "to turn" (see wry).
gal: slang pronunciation of girl, 1795, execrated as a Cockney vulgarism. Gal Friday is 1940, in reference to "Robinson Crusoe."
gala: 1625, "festive dress or attire," from Fr. en gala, from It. gala (as in phrase vestido de gala "robe of state"), perhaps from Arabic khil'a "fine garment given as a presentation." Sense of "festive occasion" (characterized by display of finery) first recorded 1777.
galaxy: late 14c., from L.L. galaxias "Milky Way," from Gk. galaxis (adj.), from gala (gen. galaktos) "milk" (see lactation). The technical astronomical sense emerged 1848. Fig. sense of "brilliant assembly of persons" is from 1580s. Milky Way is a translation of L. via lactea.
"See yonder, lo, the Galaxyë Which men clepeth the Milky Wey, For hit is whyt." [Chaucer, "House of Fame"]
Galbraith: surname, from O.Gael. Gall-Bhreathnach "stranger-Briton," a name given to Britons settled among Gaels.
gale: "storm at sea," c.1547, from gaile "wind," origin uncertain, perhaps from O.N. gol "breeze," or O.Dan. gal "bad, furious" (often used of weather), from O.N. galinn "bewitched." Or perhaps it is from O.E. galan "to sing" (the second element in nightingale), or giellan "to yell." In technical meteorological use, a wind between 32 and 63 miles per hour.
Galilee: "northernmost province of Palestine," c.1186, from L. Galilaea, Gk. Galilaia, from Heb. Haggalil, lit. "The District," a compressed form of Gelil haggoyim "the District of Nations" (cf. Isa. viii:23). The adj. Galilean is used both of Christ (1637), who was born there, and of the It. astronomer Galileo (1727) who so shook the Christian Church.
gall (1): "bile," O.E. galla (Anglian), gealla (W. Saxon), from P.Gmc. *gallon- (cf. O.N. gall, O.H.G. galla), from PIE base *ghol-/*ghel- "gold, yellow, yellowish-green" (cf. Gk. khole, see cholera; L. fel; perhaps also O.E. geolo "yellow," Gk. khloros). Informal sense of "impudence, boldness" first recorded Amer.Eng. 1882; but meaning "embittered spirit, rancor" is from c.1200.
gall (2): "sore spot on a horse," O.E. gealla "painful swelling," from L. galla "gall, lump on plant," originally "oak apple," of uncertain origin. Perhaps from or influenced by gall (1) on notion of "poison-sore." The verb meaning "to make sore by chafing" is from c.1440; fig. sense of "harass, irritate" is from 1573.
Gallagher: surname, from Ir. Gallchobhar "foreign-help."
gallant (adj.): c.1420, from O.Fr. galant "courteous," earlier "spirited, dashing," prp. of galer "make merry," from gala (q.v.). Sense of "politely attentive to women" was adopted from Fr. 17c. The noun, "man of fashion and pleasure," is from 1388.
galleon: 1529, from O.Fr. galion, from Sp. galeón "galleon, armed merchant ship," from Byzantine Gk. galea "galley" (see galley) + augmentive suffix -on.
gallery: 1500, from M.Fr. galerie "a long portico," from M.L. galeria, of uncertain origin, perhaps alteration of galilea "church porch," which is probably from L. Galilaea "Galilee," the northernmost region of Palestine; church porches sometimes were so called from being at the far end of the church. Sense of "building to house art" first recorded 1591; that of "people who occupy a (theater) gallery" (contrasted with "gentlemen of the pit") first by Lovelace, 1649, hence to play to the gallery (1872).
"Super altare Beatæ Mariæ in occidentali porte ejusdem ecclesiæ quæ Galilæ a vocatur." [c.1186 charter in "Durham Cathedral"]
galley: c.1300, from O.Fr. galie, from M.L. galea, from Late Gk. galea, of unknown origin. The word has made its way into most Western European languages. Originally "low flat-built seagoing vessel of one deck," once common in the Mediterranean; meaning "cooking range on a ship" dates from 1750. The printing sense is from 1652, from Fr. galée in the same sense, in reference to the shape of the oblong tray that holds the type. As a short form of galley-proof it is attested from 1890. To knock something or someone galleywest is Amer.Eng. slang (1875, originally in Mark Twain), a corruption of western England dialectal collyweston, name of a village in Northamptonshire that somehow came to signify "askew, not right."
Gallic: 1672, from L. Gallicus "pertaining to Gaul or the Gauls," from L. Gallia "Gaul" and Gallus "a Gaul" from a native Celtic name (see Gaelic), though some connect the word with prehistoric W.Gmc. *walkhoz "foreigners" (see Welsh). Originally used in Eng. rhetorically or mockingly for "French." Gallicism "French word or idiom" is from 1656.
gallimaufry: "a medley," 1551, from Fr. galimafrée "hash, ragout," from O.Fr. calimafree "sauce made of mustard, ginger, and vinegar; a stew of carp;" origin unknown, perhaps from O.Fr. galer "to make merry, live well" + O.N.Fr. mafrer "to eat much," from M.Du. maffelen. Others see the proper name Maufré.
gallivant: 1819, probably a playful elaboration of gallant in an obsolete verbal sense of "play the gallant, flirt, gad about."
gallon: c.1300, from O.N.Fr. galon, corresponding to O.Fr. jalon "liquid measure," related to M.L. dim. form galleta "bucket, pail," also "a measure of wine," perhaps from Gaul. galla "vessel."
gallop: 1523, from M.Fr. galoper, from O.Fr. galop (11c.), cognate of O.N.Fr. waloper, from Frank. *wala hlaupan "to run well" (see wallop).
Galloway: district in southwestern Scotland, M.L. Gallovidia, from Welsh Gallwyddel, Ir. Gallgaidhil, lit. "foreign Gaels."
gallows: c.1230, pl. of M.E. galwe "gallows," from O.N. galgi, or from O.E. galga (Mercian), gealga (W. Saxon); all from P.Gmc. *galg- "pole" (cf. O.Fris. galga, M.H.G. galge "gallows, cross"), perhaps cognate with Lith. zalga "pole, perch," Armenian dzalk "pole." Originally also used of the cross of the crucifixion. Plural because made of two poles.
Gallup poll: 1940, from George H. Gallup (1901-1984), U.S. journalist and statistician, who in 1935 set up the American Institute of Public Opinion.
galoot: "awkward or boorish man," 1812, nautical, "raw recruit, green hand," originally a sailor's contemptuous word for soldiers or marines, of uncertain origin. "Dictionary of American Slang" proposes galut, Sierra Leone creole form of Sp. galeoto "galley slave." Perhaps rather Du. slang kloot "testicle," klootzak "scrotum," used figuratively as an insult.