Origin and history of stuffy

early 14c., stuffe, "quilted material worn under chain mail," from Old French estoffe "quilted material, furniture, provisions" (Modern French étoffe), from estoffer "to equip or stock," which is of obscure origin; according to French sources it is from Old High German stopfon "to plug, stuff," or from a related Frankish word (see stop (v.)), but OED finds this "open to strong objections."

The sense was extended to material for working with in various trades (c. 1400), also "military stores and supplies" (early 15c.), then "goods or possessions generally, movable property" (mid-15c.), also "provisions or articles of food."

As a general designation for "substance or matter of an unspecified kind, physical or abstract" it is attested by mid-15c. It is by 1550s in the figurative sense of "what a person is 'made of;' " the sense of "substance (physical or abstract) of which a thing is made or consists" is by 1580s.

From 1570s as "worthless ideas," often in stuff and nonsense (by 1749, Fielding). The meaning "narcotic, dope, drug" is attested from 1929. To know (one's) stuff "have a grasp on a subject" is recorded from 1927.

very common adjective suffix, "full of, covered with, or characterized by" the thing expressed by the noun, Middle English -i, from Old English -ig, from Proto-Germanic *-iga-, from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Germanic cognates include Dutch, Danish, German -ig, Gothic -egs.

It was used from 13c. with verbs (drowsy, clingy), and by 15c. with other adjectives (crispy). Chiefly with monosyllables; with more than two the effect tends to become comedic.

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Variant forms in -y for short, common adjectives (vasty, hugy) helped poets after the loss of grammatically empty but metrically useful -e in late Middle English. Verse-writers adapted to -y forms, often artfully, as in Sackville's "The wide waste places, and the hugy plain." (and the huge plain would have been a metrical balk).

After Coleridge's criticism of it as archaic artifice, poets gave up stilly (Moore probably was last to make it work, 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 survives, he writes, only in imitation of Shakespeare; cooly and moisty (Chaucer, hence Spenser) he regards as fully obsolete. But in a few cases he notes (haughty, dusky) they seem to have supplanted shorter forms.