PERITONEUM
peritoneum
(noun) a transparent membrane that lines the abdominal cavity in mammals and covers most of the viscera
Source: WordNet® 3.1
Etymology
Noun
peritoneum (plural peritoneums or peritonea)
(anatomy) In mammals, the serous membrane lining the cavity of the abdomen and that is folded over the viscera.
(zoology) In animals, the membrane lining the coelom cavity.
Source: Wiktionary
Per`i*to*ne"um, n. Etym: [L. peritoneum, peritonaeum, Gr. (Anat.)
Definition: 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 peritonæum.]
Source: Webster’s Unabridged Dictionary 1913 Edition