mesothelium

noun, plural mes·o·the·li·a [mez-uh–thee-lee-uh, mes-, mee-zuh-, -suh-] /ˌmɛz əˈθi li ə, ˌmɛs-, ˌmi zə-, -sə-/. Anatomy, Embryology.

1. epithelium of mesodermal origin, which lines the body cavities.

noun plural -liums or -lia (-lɪə)

1. epithelium, derived from embryonic mesoderm lining body cavities

n. pl. mes•o•the•li•a (-lē-ə)

1. The layer of flat cells of mesodermal origin that lines the embryonic body cavity and gives rise to the squamous cells of the peritoneum, pericardium, and pleura.

Plural mesothelia

1. A layer of flattened epithelial cells that lines the membranes of closed body cavities, including the pericardium, pleurae, and peritoneum. Compare endothelium.