abdomen

Etymology

First attested in 1541. Borrowed from Middle French abdomen, from Latin abdomen, possibly from abdō (“conceal”), from ab (“away”) + *dĕre (“to put, place”).

noun

1. (obsolete) The fat surrounding the belly.
2. (anatomy) 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. (anatomy) 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. (zoology, entomology) The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda.