peri·ton·eumBrE/ˌperɪtəˈniəm/NAmE/ˌperɪtəˈniəm/noun (peri·ton·eums or peri·ton·eaBrE/ˌperɪtəˈniə/NAmE/ˌperɪtəˈniə/) (anatomy解剖学) themembrane on the inside of the abdomen(= verythinlayeroftissue)ontheinsideoftheabdomenthatcoversthestomachandotherorgans腹膜