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