villus

plural villi

1. biologyA small projection from a membrane, particularly those found in the mucous membranes of the intestines.

   Studies of the viable blood cells with phase contrast microscopy showed peculiar cells that had numerous short villi and were arbitrarily called “hairy cells.”

   1966 February 28, Robert Schrek, ““Hairy” Cells in Blood in Lymphoreticular Neoplastic Disease and “Flagellated” Cells of Normal Lymph Nodes”, in Blood, volume 27, number 2, page 199

   1 more example

   where a villus comes next to a gland the short cubical cells of the gland may be traced into the columnar cells of the villus , the hyaline border becoming more marked

   1880, Arthur Gamgee, A Text-book of the physiological chemistry […]

2. biologyOne of the fine soft hairs on fruits, flowers, and other parts of plants.