"wool coat of a sheep," Old English fleos, flies "fleece, wool, fur, sealskin," from West Germanic *flusaz (source also of Middle Dutch vluus, Dutch vlies, Middle High German vlius, German Vlies), which is of uncertain origin; probably from PIE *pleus- "to pluck," also "a feather, fleece" (source also of Latin pluma "feather, down," Lithuanian plunksna "feather").
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; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy). Adjectives such as hugy, vasty are artificial words that exist for the sake of poetical metrics.
<a href="https://www.etymonline.com/word/fleecy">Etymology of fleecy by etymonline</a>
Harper, D. (n.d.). Etymology of fleecy. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/fleecy