tegument
/ˈtɛɡ.jʊ.mənt/
Something which covers; a covering or coating.
1658: But in the Homericall Urne of Patroclus, whatever was the solid Tegument, we finde the immediate covering to be a purple peece of silk — Sir Thomas Browne, Urne-Burial (Penguin 2005, p. 21)
A natural covering of the body or of a bodily organ; an integument.