Integument
Integument , noun
[Latin integumentum, from integere to cover; pref. in- in, on + tegere to cover: compare French intégument. See 1st n-, and Tegument.]
(Anatomy) That which naturally invests or covers another thing, as the testa or the tegmen of a seed; specifically (Anatomy), a covering which invests the body, as the skin, or a membrane that invests a particular part.