Online Etymology Dictionary

Greenwich: town on the south bank of the Thames adjoining London, Old English Grenewic (964), literally "Green Harbor." The Royal Observatory there founded June 22, 1675, by King Charles II specifically to solve the problem of finding longitude while at sea.

In October 1884, at the behest of the President of the U.S.A., 41 delegates from 25 nations met in Washington, D.C., for the International Meridian Conference. They decided to adopt a single world meridian, passing through the principal Transit Instrument at the observatory at Greenwich, as the basis of calculation for all longitude and a worldwide 24-hour clock. The Greenwich motion passed 22-1; San Domingo voted against it; France and Brazil abstained. Greenwich Village quarter of New York City has been symbolic of "American bohemia" at least since 1903.
greet (v.): Old English gretan "to come in contact with" (in sense of "attack, accost" as well as "salute, welcome," and "touch, take hold of, handle"), from West Germanic *grotjan (cf. Old Saxon grotian, Old Frisian greta, Dutch groeten, Old High German gruozen, German grüßen "to salute, greet"), perhaps originally "to resound" (via notion of "cause to speak"), causative of Proto-Germanic *grætanan, root of Old English grætan (Anglian gretan) "weep, bewail," from PIE *gher- "to call out." Greet still can mean "cry, weep" in Scottish & northern England dialect, though this might be from a different root. Grætan is probably also the source of the second element in regret. Related: Greeted; greeting.
greeter (n.): late 14c., agent noun from greet.
greeting (n.): Old English greting "salutation," verbal noun from gretan (see greet). Related: Greetings. First record of greeting card is from 1876.
gregarious (adj.): 1660s, "living in flocks" (of animals), from Latin gregarius "pertaining to a flock; of the herd, of the common sort, common," from grex (genitive gregis) "flock, herd," reduplication of PIE root *ger- "to gather together, assemble" (cf. Greek ageirein "to assemble," agora "assembly;" Old Church Slavonic grusti "handful;" Lithuanian gurgulys "chaos, confusion," gurguole "crowd, mass"). Sense of "sociable" first recorded 1789. Related: Gregariously; gregariousness.
Gregorian (adj.): literally "pertaining to Gregory," from Late Latin Gregorianus, from Gregorius (see Gregory). From c.1600 in reference to church music, from Gregory I (pope from 590-600), who traditionally codified it; 1640s in reference to new calendar (introduced 1582) from Pope Gregory XIII.
Gregory: masc. proper name, common in England and Scotland by mid-12c. (Pope Gregory I sent the men who converted the English to Christianity), from Late Latin Gregorius, from Greek gregorios, a derivative of gregoros "to be watchful," from PIE root *ger- "to be awake" (cf. Sanskrit jagarti "he is awake," Avestan agarayeiti "wakes up, rouses"). At times confused with Latin gregarius (see gregarious).
gremlin (n.): "small imaginary creature blamed for mechanical failures," oral use in R.A.F. aviators' slang from Malta, Middle East and India said to date to 1923. First printed use perhaps in poem in journal "Aeroplane" April 10, 1929; certainly in use by 1941, and popularized in World War II and picked up by Americans (e.g. "New York Times" Magazine April 11, 1943). Of unknown origin. Speculations in Barnhart are a possible dialectal survival of Old English gremman "to anger, vex" + the -lin of goblin; or Irish gruaimin "bad-tempered little fellow." Surfer slang for "young surfer, beach trouble-maker" is from 1961 (short form gremmie by 1962).
Grenada: W. Indies island, discovered by Columbus Aug, 15, 1498, and named by him Concepción, the place later was renamed for the old Spanish kingdom or city of Granada, which is said to be from Latin granatum "pomegranate," either from fruit grown in the region or from some fancied resemblance. Others connect the name to Moorish karnattah. The Roman name, Illiberis, is said to be Iberian and represent cognates of Basque hiri "town" + berri "new," and survive in the name of the surrounding Sierra Elvira.
grenade (n.): "small explosive shell," 1590s, earlier "pomegranate" (1520s), from Middle French grenade "pomegranate" (16c.), earlier grenate (12c.), from Old French pomegrenate (influenced by Spanish granada); so called because the many-seeded fruit suggested the powder-filled, fragmenting bomb, or from similarities of shape. See pomegranate.
grenadier (n.): 1670s, originally a word for soldiers "who were dexterous in flinging hand-granados" [Evelyn], from French grenadier (15c.), from Middle French grenade "grenade" (see grenade); later "the tallest and finest men in the regiment" [OED].
grenadine (n.): 1896, from French sirop de grenadin "syrup made from pomegranates," from Middle French grenade "pomegranate" (see pomegranate).
Gretchen: fem. proper name, German diminutive of Greta, a German and Swedish pet form of Margaret. Somestimes used as a typical German female name, also sometimes in reference to the name of the simple girl seduced by Faust.
Gretna Green: town in Scotland just across the border, proverbial from late 18c. as the customery place for English couples to run off and be married without parental consent.
grew: past tense of grow, from Old English greow, past tense of growan.
grey: see gray.
greyhound (n.): Old English grighund, from grig- "bitch" + hund "dog" (see hound (n.)). The name usually is said to have nothing to do with color, and most are not gray. The Old Norse form of the word is preserved in Hjalti's couplet that almost sparked war between pagans and Christians in early Iceland:
Vilkat goð geyja
grey þykkjumk Freyja

I will not blaspheme the gods,
but I think Freyja is a bitch
grid (n.): 1839, shortening of gridiron. City planning sense is from 1954 (hence gridlock). Meaning "network of transmission lines" first recorded 1926.
griddle (n.): shallow frying pan, early 13c., apparently from Anglo-French gridil, Old North French gredil, altered from Old French graille, from Latin craticula (see grill).
gridiron (n.): cooking utensil, early 14c., griderne, alteration (by association with iron) of gridire (late 13c.), a variant of gridil (see griddle). Confusion of "l" and "r" was common in Norman dialect. Also a medieval instrument of torture by fire. As the word for a U.S. football field, by 1896, for its lines.
gridlock: 1980 (n.); 1987 (v.); from grid + lock. Related: Gridlocked; gridlocking.
grief (n.): early 13c., "hardship, suffering, pain, bodily affliction," from Old French grief "wrong, grievance, injustice, misfortune, calamity" (13c.), from grever "afflict, burden, oppress," from Latin gravare "to cause grief, make heavy," from gravis "weighty" (see grave (adj.)). Meaning "mental pain, sorrow" is from c.1300.
grievance (n.): c.1300, "state of being aggrieved," from Old French grevance "harm, injury, misfortune, trouble, suffering," from grever "to harm, to burden" (see grieve). In reference to a cause of such a condition, from late 15c.
grieve (v.): early 13c., "cause pain," from tonic stem of Old French grever "to burden, oppress, aggravate" (see grief). Meaning "be very sad, lament" is from c.1300. Related: Grieved; grieving.
griever (n.): "one who causes grief," 1590s, agent noun from grieve. Meaning "one who feels grief" is from 1819.
grieving (adj.): mid-15c., "causing pain," present participle adjective from grieve. Meaning "feeling pain" is from 1807.
grievous (adj.): c.1300, from Anglo-French grevous (Old French grevos) "heavy, hard, toilsome," from grief (see grief). Legal term grievous bodily harm attested from 1803.
grievously (adv.): mid-14c., from grievous + -ly (2).
grievousness (n.): c.1300, from grievous + -ness.
griffin (n.): c.1200 (as a surname), from Old French grifon "a bird of prey," also "fabulous bird of Greek mythology" (with head and wings of an eagle, body and hind quarters of a lion, believed to inhabit Scythia and guard its gold), from Late Latin gryphus, misspelling of grypus, variant of gryps (genitive grypos), from Greek gryps (genitive grypos) "curved, hook-nosed," in reference to its beak.

Klein suggests a Semitic source, "through the medium of the Hittites," and cites Hebrew kerubh "a winged angel," Akkad. karibu, epithet of the bull-colossus (see cherub). The same or an identical word was used, with uncertain connections, in mid-19c. Louisiana to mean "mulatto" (especially one one-quarter or two-fifths white) and in India from late 18c. to mean "newly arrived European."
Griffith: masc. proper name, from Welsh Gruffydd, probably from Latin Rufus, from rufus "red."
griffon: see griffin.
grift: 1906 (n.); 1915 (v.), U.S. underworld slang, perhaps a corruption of graft (2).
grifter (n.): "confidence trickster," 1906, carnival and circus slang, probably an alteration of grafter (see graft (n.2); also cf. grift). Gradually extended to "any non-violent criminal."
grill (n.): "gridiron," 1680s, from French gril, from Old French greil, alteration of graille "grill, frating, railings, fencing," from Latin craticula "gridiron, small griddle," diminutive of cratis "wickerwork," perhaps from PIE *kert- "to turn, entwine." In many instances, Modern English grill is a shortened form of grille, such as "chrome front of an automobile."
grill (v.): "to broil on a grill," 1660s, from grill (n.); figurative sense from 1842, and the specific (transitive) sense of "to subject to intense questioning" is first attested 1894. Related: Grilled; grilling.
grille (n.): "ornamental grating," 1660s, from French grille (fem.) "grating," from Old French greille "gridiron," from Latin craticula "gridiron" (see grill). "The distinction in French between grille and grill ... appears to date from about the 16th c." [OED].
grim (adj.): Old English grimm "fierce, cruel, savage, dire, painful," from Proto-Germanic *grimmaz (cf. Old Saxon, Old Frisian, Old High German, German grimm, Old Norse grimmr, Swedish grym "fierce, furious"), from PIE *ghrem- "angry," perhaps imitative of the sound of rumbling thunder (cf. Greek khremizein "to neigh," Old Church Slavonic vuzgrimeti "to thunder," Russian gremet' "thunder").

A weaker word now than once it was; sense of "dreary, gloomy" first recorded late 12c. It also had a verb form in Old English, grimman (class III strong verb; past tense gramm, p.p. grummen). Old English also had a noun, grima "goblin, specter," perhaps also a proper name or attribute-name of a god, hence its appearance as an element in place names.

Grim reaper as a figurative way to say "death" is attested by 1847 (the association of grim and death goes back at least to 17c.). A Middle English expression for "have recourse to harsh measures" was to wend the grim tooth (early 13c.).
grim (n.): "spectre, bogey, haunting spirit," 1620s, from grim (adj.).
grimace (n.): 1650s, from French grimace, from Middle French grimache, from Old French grimuce "grotesque face, ugly mug," possibly from Frankish (cf. Old Saxon grima "face mask," Old English grima "mask, helmet"), from same Germanic root as grim (adj.). With pejorative suffix -azo (from Latin -aceus).
grimace (v.): 1762, from French grimacer, from grimace (see grimace (n.)). Related: Grimaced; grimacing.
grimalkin (n.): 1620s, name given to a cat (cf. Shakespeare's Gray-Malkin, in "Macbeth," 1605), hence any cat, especially an old she-cat; from gray + Malkin, diminutive of fem. proper name Matilda or Maud.
grime (n.): 1580s, of uncertain origin, probably alteration of Middle English grim "dirt, filth" (early 14c.), from Middle Low German greme "dirt," from Proto-Germanic *grim- "to smear" (cf. Flemish grijm, Middle Dutch grime "soot, mask"), from PIE root *ghrei- "to rub." The verb was Middle English grymen (mid-15c.) but was replaced early 16c. by begrime.
grimly: Old English grimlic (adj.) "fierce, bloodthirsty, cruel," grimlice (adv.); see grim + -ly. Cf. Middle Dutch grimmelijc, Old Norse grimmligr.
grimness (n.): Old English grimnesse; see grim + -ness.
grimoire (n.): magician's manual for invoking demons, 1849, from French grimoire, altered from grammaire "grammar" (see grammar). Cf. glamor.
grimy (adj.): 1610s, from grime + -y (2). "App[arently] not in literary use during the 18th c." [OED]. Related: Griminess.
grin (n.): 1630s, from grin (v.).
grin (v.): Old English grennian "show the teeth" (in pain or anger), common Germanic (cf. Old Norse grenja "to howl," grina "to grin;" Dutch grienen "to whine;" German greinen "to cry"), from PIE root *ghrei- "be open." Sense of "bare the teeth in a broad smile" is late 15c., perhaps via the notion of "forced or unnatural smile." Related: Grinned; grinning.
Grinch (n.): "spoilsport;" all usages trace to Dr. Seuss' 1957 book "How the Grinch Stole Christmas."