furry (adj.)

late 14c. "trimming or lining of a garment" (implied c. 1300 in surname Furhode "fur hood"), probably from Old French forrer, fourrer "cover with fur, line (clothing)," in general "to cover, fill with," from fuerre "sheath, scabbard" (via notion of "covering"), from Frankish *fodr or another Germanic source, from Proto-Germanic *fodram "sheath" (source also of Old Frisian foder "coat lining," Old High German fotar "a lining," German Futter, Gothic fodr "sword sheath"), from PIE root *pa- "to feed, protect."

First applied c. 1400 to the hairy pelt of an animal, whether still on the animal or not. The Old French noun might have had the sense "hide, fur, pelt" (and thus might serve as the immediate source of the English noun), but this is not attested. Absent this, the sense transfer from the lining to the material that goes to make it probably happened in English. As an adjective from 1590s.

I'le make the fur Flie 'bout the eares of the old Cur. [Butler, "Hudibras," 1663]

adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic).

Originally added to nouns in Old English; it was used from 13c. with verbs, and by 15c. with other adjectives (for example crispy).

Variant forms in -y for short, common adjectives (vasty, hugy) helped poets keep step with classical feet when the grammatically empty but metrically useful -e dropped off such words in late Middle English. To replace it, by Elizabethan times, verse-writers had adapted to -y forms, and often it was done artfully, as in Sackville's "The wide waste places, and the hugy plain." Simple huge plain would have been a metrical balk.

After Coleridge's criticism of the -y forms as archaic artifice, poets gave up stilly (Moore probably was last to get away with it, with "Oft in the Stilly Night"), paly (which Keats and Coleridge himself had used) and the rest. Jespersen ("Modern English Grammar," 1954) also lists bleaky (Dryden), bluey, greeny, and other color words, lanky, plumpy, stouty, and the slang rummy. Vasty survived, he said, only in imitation of Shakespeare; cooly and moisty (Chaucer, hence Spenser) he regarded as fully obsolete. But in a few cases he notes (haughty, dusky) they seem to have supplanted the shorter forms.