tegmen

A covering or integument, usually referring to a thin layer or membrane in an organism.

An integument such as the inner membrane of the coat of a seed.

A covering such as the thin layer of bone in the roof of the middle ear of mammals.

In insects such as winged cockroaches and locusts, the stiff, membranous fore wings; in many species they are not primarily used for flight, but serve as protective covering for the delicate hind wings, which are the main organs of flight.