Integument

[Sarah]

That which naturally invests or covers another thing, as thetesta or the tegmen of a seed; specifically (Anat.), a covering whichinvests the body, as the skin, or a membrane that invests aparticular.

[Sarah]

The general term in biology that refers most commonly to the covering of an organism or organ,such as skin ,membrane,or cuticle.
(Botany):the outer layer of an ovule which later develops into the seed coat.
(Derived terms):integumentary.

[Dave Paprocki]

A tough outer protective layer, especially that of an animal or plant.

[Julian]

an outer covering, for example a skin or shell