(Anat.) The kneecap; the kneepan; the cap of the knee.
3.
(Zool.) A genus of marine gastropods, including many species of limpets. The shell has the form of a flattened cone. The common European limpet (Patella vulgata) is largely used for food.
4.
(Bot.) A kind of apothecium in lichens, which is orbicular, flat, and sessile, and has a special rim not a part of the thallus.
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