Integument

n. natural protective covering, outer coating (Anatomy, Zoology, Botany)

In zootomy, the integumentary system is the external covering of the body, comprising the skin, hair, feathers, scales, nails, sweat glands and their products (sweat and mucus). The integumentary system has a variety of functions; in animals, it may serve to waterproof, cushion and protect the deeper tissues, excrete wastes, regulate temperature and are the location of sensory receptors for pain, pressure and temperature. The name derives from the Latin integumentum, which means 'a covering'.
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Integument /in·teg·u·ment/ a covering or investment. common integument the covering of the body, or skin, including its various layers and their [more]Integument - Community and Resources

Noun
1. an outer protective covering such as the skin of an animal or a cuticle or seed coat or rind or shell
(hypernym) covering, natural covering, cover

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