Main Entry: ep·i·the·li·um

Pronunciation: \ˌe-pə-ˈthē-lē-əm\

Function: noun

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

Etymology: New Latin, from epi- + Greek thēlē nipple — more at feminine

Date: 1748

1 : 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
2 : a usually thin layer of parenchyma that lines a cavity or tube of a plant