In animals, a multilayered, extracellular, external body covering, usually composed of fibrous molecules such as chitin or collagen, and sometimes strengthened by the deposition of minerals such as calcium carbonate. In arthropods it is firm enough to act as a skeleton. In vertebrates, stratum corneum, which is cellular, is occasionally called cuticle.
A waxy layer that seals the outer surface of land plants, helping to retain moisture.