tegument
n.
"a covering, a natural protection of the body or some part of it," mid-15c., from Latin tegumentum "a covering, a cover," from tegere "to cover," from PIE root *(s)teg- (2) "to cover" (see stegosaurus). Related: Tegumentary.
〔李〕[teg;-u-;-mentn.] n.皮； 外皮，被膜； 壳 ←teg,tect (L tegere,tectum)=to cover 掩盖