abdomen

1. The belly, or that part of the body between the thorax and the pelvis, not including the back; or in some lower vertebrates, the portion between the cardiac and caudal regions.
2. The cavity of the belly, which is lined by the peritoneum, and contains the viscera; often restricted in humans to the part between the diaphragm and the commencement of the pelvis, the remainder being called the pelvic cavity. · He was all bent over complaining of pains in the abdomen.
3. The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda.

Plural abdomens