Online Etymology Dictionary

glandular (adj.): 1740, from French glandulaire, from glandule "small gland" (16c.), from Latin glandula (see gland).
glans (n.): 1640s, from Latin glans "acorn" (see gland).
glare (v.): late 13c., "shine brightly," from or related to Middle Dutch, Middle Low German glaren "to gleam," related by rhoticization to glas (see glass). Sense of "stare fiercely" is from late 14c. The noun is c.1400 in sense "bright light;" 1660s in sense of "fierce look." Old English glær (n.) meant "amber." Related: Glared; glaring.
glaring (adj.): late 14c., from present participle of glare. Meaning "obtrusively conspicuous" is from 1706.
Glasgow: from Gaelic, literally "green hollow," from gael "green" + cau "hollow."
glasnost (n.): 1972 (in reference to a letter of 1969 by Solzhenitsyn), from Russian glasnost "openness to public scrutiny," literally "publicity, fact of being public," ultimately from Old Church Slavonic glasu "voice" (see call). First used in a socio-political sense by Lenin; popularized in English after Mikhail Gorbachev used it prominently in a speech of March 11, 1985, accepting the post of general secretary of the CPSU.
The Soviets, it seems, have rediscovered the value of Lenin's dictionary that "glasnost," the Russian word for openness or publicity, is a desirable form of conduct. [New York Times news service article, March 1981]
glass (n.): Old English glæs "glass, a glass vessel," from West Germanic *glasam (cf. Old Saxon glas, Middle Dutch and Dutch glas, German Glas, Old Norse gler "glass, looking glass," Danish glar), from PIE *ghel- "to shine, glitter" (cf. Latin glaber "smooth, bald," Old Church Slavonic gladuku, Lithuanian glodus "smooth"), with derivatives referring to colors and bright materials, a word that is the root of widespread words for gray, blue, green, and yellow (cf. Old English glær "amber," Latin glaesum "amber," Old Irish glass "green, blue, gray," Welsh glas "blue;" see Chloe). Sense of "drinking glass" is early 13c.

The glass slipper in "Cinderella" is perhaps an error by Charles Perrault, translating in 1697, mistaking Old French voir "ermine, fur" for verre "glass." In other versions of the tale it is a fur slipper. The proverb about people in glass houses throwing stones is attested by 1779, but earlier forms go back to 17c.:
Who hath glass-windows of his own must take heed how he throws stones at his house. ... He that hath a body made of glass must not throw stones at another. [John Ray, "Handbook of Proverbs," 1670]
glass (v.): late 14c., "to fit with glass;" 1570s, "to cover with glass," from glass (n.). Related: Glassed; glassing.
glasses (n.): "spectacles," 1660s, from plural of glass.
glassy (adj.): late 14c., from glass + -y (2).
Glastonbury: town in Somersetshire, famous as a prehistoric site, Old English Glestingabyrig, Glastingburi (725), "Stronghold (Old English byrig, dative of burh) of the people (Old English -inga-) living at Glaston," a Celtic name, possibly meaning "woad place."
glaucoma (n.): 1640s, from Greek glaukoma "cataract, opacity of the lens" (cataracts and glaucoma not distinguished until c.1705), from -oma + glaukos, an adjective of uncertain origin (see glaucous).
glaucous (adj.): "bluish-green, gray," 1670s, from Latin glaucus "bluish-green," of uncertain origin; used in Homer of the sea as "gleaming, silvery" (apparently without a color connotation); used by later writers with a sense of "bluish-green, gray," of olive leaves and eyes. Homer's glauk-opis Athene probably originally was a "bright-eyed," not a "gray-eyed" goddess. Greek for "owl" was glaux from its bright, staring eyes.
glaze (v.): mid-14c., glasen "to fit with glass," from glas (see glass), probably influenced by glazier. Noun sense of "substance used to make a glossy coating" is first attested 1784; in reference to ice, from 1752. Related: Glazed; glazing.
glazier (n.): late 14c. (late 13c. as a surname; alternative glazer recorded from c.1400), from glass + -er (1), influenced by French words in -ier.
gleam (n.): Old English glæm "brilliant light; brightness, splendor, radiance," from Proto-Germanic *glaimiz (cf. Old Saxon glimo "brightness;" Middle High German glim "spark," gleime "glowworm;" German glimmen "to glimmer, glow;" Old Norse glija "to shine, glitter"), from root *glim-, from PIE *ghel- "to shine, glitter, glow" (see glass).
gleam (v.): early 13c., from gleam (n). Related: Gleamed; gleaming.
glean (v.): early 14c., from Old French glener (Modern French glaner) "to glean," from Late Latin glennare "make a collection," perhaps from Gaulish (cf. Old Irish do-glinn "he collects, gathers," Celt. glan "clean, pure"). Figurative sense was earlier in English than the literal one of "gather grain left by the reapers" (late 14c.). Related: Gleaned; gleaning.
gleaner (n.): mid-15c., agent noun from glean (v.).
glebe (n.): c.1300, from Old French glebe, from Latin gleba, glaeba "clod, lump of earth," from PIE *glebh- "to roll into a ball" (cf. Latin globus "sphere;" Old English clyppan "to embrace;" Lithuanian glebys "armful," globti "to embrace, support"). Earliest English sense is "land forming a clergyman's benefice," on notion of soil of the earth as source of vegetable products.
glee (n.): Old English gliu, gliw "entertainment, mirth, jest, play, sport," presumably from a Proto-Germanic *gleujam but absent in other Germanic languages except for the rare Old Norse gly "joy;" probably related to glad. A poetry word in Old English and Middle English, obsolete c.1500-c.1700, it somehow found its way back to currency late 18c. In Old English, an entertainer was a gleuman (female gleo-mægden). Glee club (1814) is from the secondary sense of "unaccompanied part-song" (1650s) as a form of musical entertainment.
gleeful (adj.): 1580s, from glee + -ful. Related: Gleefully. Alternative gleesome attested from c.1600.
gleek (n.): card game, 1530s, from French glic, ghelicque (15c.), perhaps from Middle Dutch ghelic (Dutch gelijk) "like," because one of the goals of the game is collecting cards of the same rank.
gleen (n.): "gleam of sunlight," 1650s, probably from a Scandinavian dialectal word, cf. Swedish dialectal glena, Danish dialectal glene "clear patch of sky."
gleet (n.): mid-14c., from Old French glete "clay, loam; slime, mud; filth" (12c., Modern French glette), from Latin glitem (nominative glis) "sticky, glutinous ground," back-formation from glittus "sticky."
glen (n.): "narrow valley," late 15c., from Scottish, from Gaelic gleann "mountain valley" (cf. Old Irish glenn, Welsh glyn). Common in place names; cf. Glenlivet (1822), a kind of whiskey, named for the place it was first made (literally "the glen of the Livet," a tributary of the Avon); and Glengarry (1841) a kind of men's cap, of Highland origin, named for a valley in Inverness-shire.
glib (adj.): 1590s, "smooth and slippery," possibly a shortening of obsolete glibbery "slippery," which is perhaps from Low German glibberig "smooth, slippery," from Middle Low German glibberich, from or related to glibber "jelly." Of words, speakers, etc., from c.1600. Related: Glibly; glibness.
glide (v.): Old English glidan "move along smoothly and easily, glide, slip, slide" (class I strong verb, past tense glad, past participle gliden), from West Germanic *glidan "to glide" (cf. Old Saxon glidan, Old Frisian glida, German gleiten). Related: Glided; gliding. Strong past tense form glid persisted into 20c. The noun is attested 1580s, from the verb.
glider (n.): mid-15c., "person or thing that glides," agent noun from glide. Meaning "motorless airplane" is c.1897.
glim (n.): 18c. slang, "a light, candle, lantern;" 19c. slang "an eye," probably a back-formation from glimmer.
glimmer (v.): early 14c., "shine brightly," a frequentative from Proto-Germanic *glim-, root of Old English glæm "brightness" (see gleam (n.)). Sense shifted 15c. to "shine faintly." Cf. Dutch glimmeren, German glimmeren "to shine dimly." Related: Glimmered; glimmering.
glimmer (n.): 1580s, from glimmer (v.).
glimpse (v.): c.1400, "to glisten, be dazzling," probably from Old English *glimsian "shine faintly," from Proto-Germanic *glim- (see gleam). If so, the intrusive -p- would be there to ease pronunciation. Sense of "catch a quick view" first recorded mid-15c. Related: Glimpsed. The noun is recorded from mid-16c.; earlier in verbal noun glimpsing (mid-14c.).
glint (n.): 1540s (modern use from 1826), from glint (v.).
glint (v.): 1787, from Scottish, where apparently it survived as an alteration of Middle English glenten "gleam, flash, glisten" (mid-15c.), from a Scandinavian source (cf. Norwegian gletta "to look," dialectal Swedish glinta "to shine"), from Proto-Germanic *glent-, from PIE *ghel- "to shine, glitter, glow, be warm" (see glass). Reintroduced into literary English by Burns. Related: Glinted; glinting.
glioma (n.): type of brain tumor, 1870, medical Latin, literally "glue tumor," from Greek glia "glue" + -oma.
glissade: in dancing sense, 1832 (v.), 1843 (n.), from French glissade, from glisser "to slip, slide" (13c.), from a Germanic source (cf. Dutch glissen), from Proto-Germanic *glidan "to glide" (see glide).
glissando: 1873, Italianized form of French glissant, present participle of glisser (see glissade).
glisten (v.): Old English glisnian "to glisten, gleam," from Proto-Germanic *glis- (cf. Old Frisian glisa "to shine," Middle High German glistern "to sparkle," Old Danish glisse "to shine"), from PIE *ghleis-, from root *ghel- "to shine, glitter, glow, be warm" (see glass). Related: Glistened; glistening.
glister (v.): late 14c., probably from or related to Low German glisten, Middle Dutch glisteren, from PIE root *ghel- "to shine, glitter" (see glass). Related: Glistered; glistering. As a noun, from 1530s.
glitch (n.): 1962, American English, possibly from Yiddish glitsh "a slip," from glitshn "to slip," from German glitschen, and related gleiten "to glide" (see glide). Perhaps directly from German; it began as technical jargon in the argot of electronic hardware engineers, popularized and given a broader meaning by U.S. space program.
glitter (v.): c.1300, glideren (late 14c. as gliteren), from a Scandinavian source, cf. Old Norse glitra "to glitter," from glit "brightness," from Proto-Germanic *glit- "shining, bright" (cf. Old English glitenian "to glitter, shine; be distinguished," Old High German glizzan, German glitzern, Gothic glitmunjan), from PIE *ghleid- (cf. Greek khlidon, khlidos "ornament"), from root *ghel- "to shine, glitter" (see glass). Related: Glittered; glittering. The noun is c.1600, from the verb. Glitter rock is from 1972.
glitterati (n.): 1956, from glitter, with a play on literati.
glitz (n.): 1977, a back-formation from glitzy.
glitzy (adj.): 1966, from Yiddish glitz "glitter," from German glitzern "sparkle" (see glitter).
gloam: 1821 (Keats), a back-formation from gloaming.
gloaming (n.): Old English glomung "twilight," formed (probably on model of æfning "evening") from glom "twilight," related to glowan "to glow" (hence "glow of sunrise or sunset"), from Proto-Germanic *glo- (see glow (v.)). Fell from currency except in Yorkshire dialect, but preserved in Scotland and reintroduced by Burns and other Scottish writers after 1785.
gloat (v.): 1570s, "to look at furtively," from a Scandinavian source, cf. Old Norse glotta "to grin, smile scornfully, show the teeth," Swedish dialectal glotta "to peep;" or from Middle High German glotzen "to stare, gape." Sense of "to look at with malicious satisfaction" first recorded 1748. Related: Gloated; gloating. As a noun, from 1640s with sense of "side-glance;" 1899 as "act of gloating."
glob (n.): 1900, perhaps suggested by blob, gob, etc.
global (adj.): 1670s, "spherical," from globe + -al (1). Meaning "worldwide, universal" is from 1892, from French. Global village first attested 1960, popularized, if not coined, by Canadian educator Marshall McLuhan (1911-1980).
Postliterate man's electronic media contract the world to a village or tribe where everything happens to everyone at the same time: everyone knows about, and therefore participates in, everything that is happening the minute it happens. Television gives this quality of simultaneity to events in the global village. [Carpenter & McLuhan, "Explorations in Communication," 1960]