vil·lous \ˈviləs\adjective Etymology: Middle English, from Latin villosus rough, shaggy, from villus shaggy hair, tuft of hair + -osus -ous — more at velvet 1. a.: covered or furnished with villi < two villous normal human ova > b.: of the character of a villus < a villous filament > 2.: having soft long hairs < leaves villous underneath > — compare pubescent • vil·lous·lyadverb