Online Etymology Dictionary

gusty (adj.): c.1600, from gust + -y (2). Related: Gustily; gustiness.
gut (n.): Old English guttas (plural) "bowels, entrails," related to geotan "to pour," from PIE *gheu- "pour" (see found (v.2)). Related to Middle Dutch gote, Dutch goot, German Gosse "gutter, drain," Middle English gote "channel, stream." Meaning "abdomen, belly" is from c.1400. Meaning "easy college course" is student slang from 1916, probably from obsolete slang sense of "feast" (the connecting notion is "something that one can eat up"). Sense of "inside contents of anything" (usually plural) is from 1570s. To hate (someone's) guts is first attested 1918. The notion of the intestines as a seat of emotions is ancient (cf. bowel) and probably explains expressions such as gut reaction (1963), gut feeling (by 1970), and cf. guts. Gut check attested by 1976.
gut (v.): "to remove the guts of" (fish, etc.), late 14c., from gut (n.); figurative use by 1680s. Related: Gutted; gutting.
gut-bucket (adj.): in reference to jazz, "earthy," by 1929, supposedly originally a reference to the buckets which caught the drippings, or gutterings, from barrels. Which would connect it to gutter (v.).
gutless (adj.): "cowardly," 1900, from gut (n.) in the figurative "spirit" sense (see guts) + -less. Literal sense is from c.1600. Related: Gutlessly.
guts (n.): "spirit, courage," 1893, figurative plural of gut (n.). The idea of the bowels as the seat of the spirit goes back to at least mid-14c.
gutsy (adj.): "tough, plucky," 1936, from guts + -y (2). Earlier it meant "greedy" (1803).
gutta-percha (n.): 1845, from Malay getah percha, literally "the gum of percha," the name of the tree; the form of the word influenced by Latin gutta "drop." As the name of the tree itself, from 1860.
gutter (n.): late 13c., "watercourse, water drainage channel along the side of a street," from Anglo-Norman gotere, from Old French guitere, goutiere (13c., Modern French gouttière) "gutter, spout" (of water), from goute "a drop," from Latin gutta "a drop." Meaning "furrow made by running water" is from 1580s. Meaning "trough under the eaves of a roof to carry off rainwater" is from mid-14c. Figurative sense of "low, profane" is from 1818. In printers' slang, from 1841.
gutter (v.): late 14c., "to make or run in channels," from gutter (n.). In reference to candles (1706) it is from the channel that forms on the side as the molten wax flows off. Related: Guttered; guttering.
guttersnipe (n.): also gutter-snipe, 1857, from gutter (n.) + snipe (n.); originally Wall Street slang for "streetcorner broker," attested later (1869) as "street urchin," also "one who gathers rags and paper from gutters." As a name for the common snipe, it dates from 1874 but is perhaps earlier.
guttural (adj.): "pertaining to the throat," 1590s, from Middle French guttural, from Latin guttur "throat, gullet" (see bowel). The noun, in linguistics, is from 1690s.
guv: 1890, shortening of guvner, casual British pronunciation of governor as a title of respect.
guy (n.1): "rope, chain, wire," mid-14c., "leader," from Old French guie "a guide," from guier (see guide (v.)); or from a similar word in North Sea Germanic. The "rope" sense is nautical, first recorded 1620s.
guy (n.2): "fellow," 1847, originally American English; earlier (1836) "grotesquely or poorly dressed person," originally (1806) "effigy of Guy Fawkes," leader of the Gunpowder Plot to blow up British king and Parliament (Nov. 5, 1605), paraded through the streets by children on the anniversary of the conspiracy. The male proper name is from French, related to Italian Guido.
Guyana: from a native word perhaps meaning "respectable."
guyot (n.): "flat-topped submarine mountain," 1946, named for Swiss geographer/geologist Arnold Guyot (1807-1884).
guzzle (v.): 1570s, probably related to Old French gosillier "to go down the gullet; to vomit, chatter, talk," from gosier (13c.) "jaws, throat, gullet." Or imitative of the sound of drinking greedily. Related: Guzzled; guzzling. As a noun from 1590s.
guzzler (n.): 1704, agent noun from guzzle (v.).
Gwen: fem. proper name, typically short for Gwendolyn.
Gwendolyn: fem. proper name; the first element is Breton gwenn "white" (cf. Welsh gwyn, Old Irish find, Gaelic fionn, Gaulish vindo- "white, shining," literally "visible"), from nasalized form of PIE root *weid- "to see, know" (see vision).
gybe: alternative spelling of jibe.
gym (n.): short for gymnasium, attested from 1871, U.S. student slang.
gymkhana: 1861, Anglo-Indian, said to be from Hindustani gend-khana, literally "ball house;" altered in English by influence of gymnasium.
gymnasium (n.): 1590s, "place of exercise," from Latin gymnasium "school for gymnastics," from Greek gymnasion "public place where athletic exercises are practiced; gymnastics school," in plural, "bodily exercises," from gymnazein "to exercise or train," literally or figuratively, literally "to train naked," from gymnos "naked" (see naked). Introduced to German 15c. as a name for "high school" (more or less paralleling a sense in Latin); in English it has remained purely athletic.
gymnast (n.): 1590s in the modern sense, a back-formation from gymnastic. Greek gymnastes was "a trainer of professional athletes."
gymnastic (adj.): 1570s, from Latin gymnasticus, from Greek gynmastikos "fond of or skilled in bodily exercise," from gymnazein "to exercise or train" (see gymnasium).
gymnastics (n.): 1650s, from gymnastic; also see -ics.
gymno-: word-forming element meaning "naked, stripped, bare," from comb. form of Greek gymnos "naked, unclad; bare, mere" (see naked).
gymnosophist (n.): c.1400, from Greek gymnosophistai "the naked philosophers," from gymnos "naked" (see naked) + sophistes "sophist" (see sophist). Ancient Hindu holy men whose self-denial extended to clothes; they were known to the Greeks through the reports of Alexander the Great's soldiers.
gymnosperm (n.): 1830, from French gymnosperme and Modern Latin gymnospermus (17c.), literally "naked seed" (i.e., not enclosed in an ovary), from gymno- + sperma "seed" (see sprout).
gynarchy (n.): government by women or a woman, 1570s, from Greek gyne (see queen) + -arkhe (see archon). Gynaecocracy and gyneocracy attested from 1610s.
gyneco-: also gynaeco-, before a vowel gynec-, word-forming element from Greek gynaiko-, comb. form of gyne "woman, female" (see queen).
gynecological (adj.): also gynaecological, 1876, from gynecology + -ical.
gynecologist (n.): also gynaecologist, 1872, from gynecology + -ist.
gynecology (n.): also gynaecology, 1847, from French gynécologie, from Greek gynaik-, comb. form of gyne "woman, female," from PIE *gwen- "woman" (see queen). Second element is from French -logie "study of," from Greek (see -logy). Another word for it was gyniatrics.
gynecomastia (n.): 1881, from Greek gyne (see queen) + mazos "breast," variant of mastos (see masto-).
gyno-: word-forming element equivalent to gyneco-.
gyp (v.): "to cheat, swindle," 1889, American English, probably derived from the colloquial shortening of Gypsy (cf. gip). Related: Gypped. As a noun, "fraudulent action, a cheat," by 1914.
Gypsophila (n.): genus of the pink family, 1771, Modern Latin, from Greek gypsos "chalk, gypsum" (see gypsum) + philein "to love" (see philo-).
gypsum (n.): substance (hydrated calcium sulphate) used in making plaster, late 14c., from Latin gypsum, from Greek gypsos "chalk," according to Klein, perhaps of Semitic origin (cf. Arabic jibs, Hebrew gephes "plaster").
Gypsy: also gipsy, c.1600, alteration of gypcian, a worn-down Middle English dialectal form of egypcien "Egyptian," from the supposed origin of these people. As an adjective, from 1620s.

Cognate with Spanish Gitano and close in sense to Turkish and Arabic Kipti "gypsy," literally "Coptic;" but in Middle French they were Bohémien (see bohemian), and in Spanish also Flamenco "from Flanders." "The gipsies seem doomed to be associated with countries with which they have nothing to do" [Weekley]. Zingari, the Italian and German name, is of unknown origin. Romany is from the people's own language, a plural adjective form of rom "man." Gipsy is the prefered spelling in England.
gyrate (v.): 1822 (implied in gyrated), back-formation from gyration. Related: Gyrated; gyrating.
gyration (n.): 1610s, noun of action from Late Latin gyratum, past participle of gyrare, from Latin gyrus "circle" (see gyre).
gyre (n.): 1560s, "a circular motion;" as a verb, "to turn round," early 15c.; from Latin gyrus "circle, circular course, round, ring," and its derived verb gyrare, from Greek gyros "circle, ring," related to gyrós "rounded," perhaps from PIE root *geu- "to bend, curve" (cf. Armenian kor "crooked," Lithuanian gurnas "hip, ankle, bone," Norwegian kaure "a curly lock of hair").
gyrfalcon (n.): also gerfalcon, c.1200, from Old French girfauc "large northern falcon," probably from Frankish, from Proto-Germanic *ger (cf. Old High German gir "vulture") + Latin falco "hawk" (see falcon). Folk etymology connects it with Latin gyrus (see gyre) in reference to "circling" in the air.
gyro (n.): sandwich made from roasted lamb, late 20c., originally the meat itself, as roasted on a rotating spit, from Modern Greek gyros "a circle" (see gyre); mistaken in English for a plural and shorn of its -s.
gyro-: word-forming element meaning "gyrating" or "gyroscope," from comb. form of Greek gyros "ring, circle" (see gyre).
gyromancy (n.): 1550s, method of divination by walking in a circle till the person falls down from dizziness, the inference being drawn from the place in the circle at which he fell, from Medieval Latin gyromantia, from Greek gyyros "circle" (see gyre) + manteia "divination, oracle" (see -mancy).
gyroscope (n.): heavy rotating wheel with an axis free to turn in any direction, 1856, invented and named in French 1852 by Foucault, from Greek gyros "circle" (see gyre) + skopos "watcher" (see scope (n.1)), because the device demonstrates that the earth rotates.