PERITONEUM

[peri.to.ne.um] n, pl -ne.ums or -nea [ME, fr. LL, fr. Gk peritonaion, neut. of peritonaios stretched around, fr. peri- + teinein to stretch--more at thin] (15c): the smooth transparent serous membrane that lines the cavity of the abdomen of a mammal and is folded inward over the abdominal and pelvic viscera -- peri.to.ne.al adj -- peri.to.ne.al.ly adv