For the telepathic criminal, please see Villus Thed.
Villi (singular: villus) were small finger-shaped projections extending into the interior of the small intestine and related internal organs of some living beings.
In Humans, the villi increased intestinal absorptive surface area thirty-fold providing exceptionally efficient absorption of nutrients. There were also enzymes on the surface to aid digestion. Villus capillaries collected amino acids and simple sugars taken up by the villi into the bloodstream.
In 2269, Montgomery Scott cut off a piece of the living cosmic cloud's villi and used it to regenerate the ship's antimatter reserves. (TAS: "One of Our Planets Is Missing")