Fuffa is a "cosa inutile, ciarpame" [a useless thing, trash] according to Federico Roncoroni in Sillabario della Memoria (Milano, 2010). It's a dialectical (probably Milanese) word not found in most Italian dictionaries. Roncoroni tells us that his aunt Evelina called the tiny balls of material that sometimes form on the surface of socks "fuffa." She likened them to "furuncoli" [pimples]. The etymology of fuffa is obscure. Roncoroni proposes that it might be merely onomatopoeic, related to English fluff which signifies, as he says, "lanugine o peluria" [fuzz or nap]. But fluff, fuzzy stuff in English, derives from Latin vellus [fleece] or "villus" [hair]. It's most commonly used as a verb ("to fluff a pillow'). In theatrical jargon, a person can fluff or flub his lines. Fluff is also a horrid marshmallow-like confection that appeared in my childhood (though it dates to the 1920) and put me off sweets for years. As far as I can tell, the meaning "a light woman" as in "a bit of fluff" is not present in the Italian "fuffa." I doubt whether "fuffa" and "fluff" are linked, unless "fuffa" also descends from "vellus."