mid-14c., "downy plumage;" late 15c, "fine, soft hair," from Anglo-French pyle or Middle Dutch pijl, both from Latin pilus "a hair" (source of Italian pelo, Old French pel), a word of uncertain origin. Phonological evidence rules out transmission of the English word via Old French cognate peil, poil. Meaning "soft, raised surface of a regular and closely set kind upon cloth" is from 1560s.
