villus

Concise Oxford English Dictionary © 2008 Oxford University Press:
villus /ˈvɪləs/

▶noun (pl. villi /-lʌɪ, -liː/) Anatomy any of numerous minute elongated projections set closely together on a surface, especially in the absorbent lining of the small intestine.

– derivatives
villiform adjective,
villous adjective.

– origin C18: from L., lit. ‘shaggy hair’.