noun

• (zoology) A covering flap in animals, such as a gill cover.
• (botany) The lidlike portion of a moss sporangium or of a fruit that detaches to allow the dispersal of spores or seeds.
• (dentistry) A gum flap covering (part of) a partially erupted tooth, usually a wisdom tooth.
• A structure which serves as a cover or lid.
• (anatomy) One of several flaps of cerebral cortex covering the insula.