Main Entry: ep·i·the·li·um

Pronunciation: \ˌep-ə-ˈthē-lē-əm\

Function: noun

Inflected Form(s): plural ep·i·the·lia \-lē-ə\

: a membranous cellular tissue that covers a free surface or lines a tube or cavity of an animal body and serves especially to enclose and protect the other parts of the body, to produce secretions and excretions, and to function in assimilation

[epithelium illustration]