noun pl. villi vil′li′ (-ī′)

1. Anat. any of numerous hairlike or fingerlike vascular processes on certain mucous membranes of the body, as of the small intestine, serving to secrete mucus, absorb fats, etc., or of the chorion in the mammalian placenta, serving in the exchange of food materials, etc. between the mother and the fetus
2. Bot. any of the long, soft, fine hairs on certain plants, as mosses

Etymology: L, shaggy hair, tuft of hair, var. of vellus, a fleece, wool