abdomen

noun

Etymology: First attested in 1541 as labdomen. Borrowed from Middle French abdomen as well as from its etymon Latin abdōmen, possibly from abdō (“conceal”), from ab (“away”) + -dō (“put, place”).

1. The fat surrounding the belly.
2. 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.
3. 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.”

4. The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda.