Peritoneum
Pronunciation : Per`i*to*ne"um
Part of Speech : n.
Etymology : [L. peritoneum, peritonaeum, Gr. (Anat.)
Definition : Defn: The smooth serous membrane which lines the cavity of the abdomen, or the whole body cavity when there is no diaphragm, and, turning back, surrounds the viscera, forming a closed, or nearly closed, sac. [Written also periton?um.]
Source : Webster's Unabridged Dictionary, 1913