1) Serosa 2) Serous membrane 
• (a.) Of or pertaining to the peritoneum.
Having to do with the parietal peritoneum (the tissue that lines the abdominal wall and pelvic cavity) and visceral peritoneum (the tissue that covers most of the organs in the abdomen, including the intestines).
having to do with the peritoneum.
Per`i·to·ne'al adjective [ Confer French péritonéal .] (Anat.) Of or pertaining to the peritoneum. 
Type: Term Pronunciation: per′i-tō-nē′ăl Definitions: 1. Relating to the peritoneum.
Peritoneal: Having to do with the peritoneum.
[adj] - of or relating to or affecting the peritoneum
Of the peritoneum. So, peritoneal cancer is cancer of the sheet of body tissue (the peritoneum) that lines the abdominal cavity and covers the organs inside it.
adjective of or relating to or affecting the peritoneum; `peritoneal cancer`
The abdominal or belly cavity.