Definition of: abdomen

(ab′də·mən, ab·dō′mən) noun
1. In mammals, the visceral cavity between the diaphragm and the pelvic floor; the belly: in human anatomy often restricted to the cavity above the true pelvis.
2. In vertebrates other than mammals, the region or cavity that contains the viscera.
3. Entomol. The hindmost of the main divisions of the arthropod body. [<L>]
ABDOMINAL REGIONS
1. Right hypochondriac region.
2. Left hypochondriac.
3. Epigastric.
4. Umbilical.
5. Right lumbar.
6. Left lumbar.
7. Right inguinal.
8. Left inguinal.
9. Hypogastric.