1590s, "cloth having a velvet nap on one side," perhaps ultimately from Old English sceacga "rough matted hair or wool," but the word seems to be missing in Middle English. The Old English word is from Proto-Germanic *skagjan (source also of Old Norse skegg, Swedish skägg "beard"), and perhaps related to Old High German scahho "promontory," Old Norse skagi "a cape, headland," with a connecting sense of "jutting out, projecting." Also compare shaw (n.).
The meaning "rough, matted hair, wool, or the like" is from c. 1600. Of a kind of strong tobacco cut in fine shreds, from 1789; of carpets, rugs, etc. made of cloth having a long nap, from 1946.
"copulate with," 1788 (Grose), probably from obsolete verb shag (Middle English shoggen, shaggen, late 14c.) "to shake, waggle," which is of obscure origin but probably related to or an alteration of shake (v.):
And þe boot, amydde þe water, was shaggid. [Wycliffite sermon, c. 1425]
Compare shag (v.), used from 1610s in a sense "to roughen or make shaggy," from the noun shag. Also compare shake it in U.S. blues slang from 1920s, ostensibly with reference to dancing. It also was the name of a dance popular in U.S. in the 1930s and '40s. Related: Shagged; shagging.
in baseball, "to go after and catch" (fly balls), by 1913, of uncertain origin. Century Dictionary has this as a secondary sense of shag (v.) "to rove about as a stroller or beggar" (1851), which is perhaps from shack (n.) "disreputable fellow" (1680s), short for shake-rag, an old term for a beggar. But OED notes "it is not even certain that" the two verbs shag are the same.
"unkempt; having rough, coarse, long hair," 1580s, from shag (n.) + -y (2). Related: Shaggily; shagginess. Earlier was shagged, from Old English sceacgede "hairy;" compare Old Norse skeggjaðr, Danish skægget "bearded." The shaggy-dog story as a type of absurd joke built into a long, tedious story, is attested from 1943 and was a fad in the mid-40s. The origin of the phrase may be in vaudeville; the most-often cited original example involves an Englishman who offers a reward for a lost shaggy dog, an enterprising American who, with great difficulty, tracks him down and offers a shaggy dog that he claims is the one, and his curt reception: "Not that shaggy." But the story does not seem to be older than the phrase.
"soft fabric, cloth having a softer and longer nap than that of velvet," 1590s, from French pluche "shag, plush," contraction of peluche "hairy fabric," from Old French peluchier "to pull, to tug, to pluck" (the final process in weaving plush), from Vulgar Latin *piluccare "remove hair" (see pluck (v.)). Related: Plushy; plushness.
1937, coined in the fantasy tales of J.R.R. Tolkien (1892-1973).
On a blank leaf I scrawled: 'In a hole in the ground there lived a hobbit.' I did not and do not know why. [Tolkien, letter to W.H. Auden, dated 1955]
The word also turns up in a very long list of folkloric supernatural creatures in the writings of Michael Aislabie Denham (d. 1859) as an aside to his explanation that those born on Christmas Eve cannot see spirits. Denham was an early folklorist who concentrated on Northumberland, Durham, Westmoreland, Cumberland, the Isle of Man, and Scotland. This was printed in volume 2 of "The Denham Tracts" [ed. James Hardy, London: Folklore Society, 1895], a compilation of Denham's scattered publications.
What a happiness this must have been seventy or eighty years ago and upwards, to those chosen few who had the good luck to be born on the eve of this festival of all festivals; when the whole earth was so overrun with ghosts, boggles, bloody-bones, spirits, demons, ignis fatui, brownies, bugbears, black dogs, specters, shellycoats, scarecrows, witches, wizards, barguests, Robin-Goodfellows, hags, night-bats, scrags, breaknecks, fantasms, hobgoblins, hobhoulards, boggy-boes, dobbies, hob-thrusts, fetches, kelpies, warlocks, mock-beggars, mum-pokers, Jemmy-burties, urchins, satyrs, pans, fauns, sirens, tritons, centaurs, calcars, nymphs, imps, incubuses, spoorns, men-in-the-oak, hell-wains, fire-drakes, kit-a-can-sticks, Tom-tumblers, melch-dicks, larrs, kitty-witches, hobby-lanthorns, Dick-a-Tuesdays, Elf-fires, Gyl-burnt-tales, knockers, elves, rawheads, Meg-with-the-wads, old-shocks, ouphs, pad-foots, pixies, pictrees, giants, dwarfs, Tom-pokers, tutgots, snapdragons, sprets, spunks, conjurers, thurses, spurns, tantarrabobs, swaithes, tints, tod-lowries, Jack-in-the-Wads, mormos, changelings, redcaps, yeth-hounds, colt-pixies, Tom-thumbs, black-bugs, boggarts, scar-bugs, shag-foals, hodge-pochers, hob-thrushes, bugs, bull-beggars, bygorns, bolls, caddies, bomen, brags, wraiths, waffs, flay-boggarts, fiends, gallytrots, imps, gytrashes, patches, hob-and-lanthorns, gringes, boguests, bonelesses, Peg-powlers, pucks, fays, kidnappers, gallybeggars, hudskins, nickers, madcaps, trolls, robinets, friars' lanthorns, silkies, cauld-lads, death-hearses, goblins, hob-headlesses, bugaboos, kows, or cowes, nickies, nacks necks, waiths, miffies, buckies, ghouls, sylphs, guests, swarths, freiths, freits, gy-carlins Gyre-carling, pigmies, chittifaces, nixies, Jinny-burnt-tails, dudmen, hell-hounds, dopple-gangers, boggleboes, bogies, redmen, portunes, grants, hobbits, hobgoblins, brown-men, cowies, dunnies, wirrikows, alholdes, mannikins, follets, korreds, lubberkins, cluricauns, kobolds, leprechauns, kors, mares, korreds, puckles korigans, sylvans, succubuses, blackmen, shadows, banshees, lian-hanshees, clabbernappers, Gabriel-hounds, mawkins, doubles, corpse lights or candles, scrats, mahounds, trows, gnomes, sprites, fates, fiends, sibyls, nicknevins, whitewomen, fairies, thrummy-caps, cutties, and nisses, and apparitions of every shape, make, form, fashion, kind and description, that there was not a village in England that had not its own peculiar ghost. Nay, every lone tenement, castle, or mansion-house, which could boast of any antiquity had its bogle, its specter, or its knocker. The churches, churchyards, and crossroads were all haunted. Every green lane had its boulder-stone on which an apparition kept watch at night. Every common had its circle of fairies belonging to it. And there was scarcely a shepherd to be met with who had not seen a spirit!
[Emphasis added] It is curious that the name occurs nowhere else in folklore, and there is no evidence that Tolkien ever saw this. The word also was recorded from 1835 as "a term generally used in Wales to express a quantity made up of four Welsh pecks" [in English court records for Hughes vs. Humphreys, a weights-and-measures case]. Hobbitry attested from 1947.