Abdomen

1. n. The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda.
2. n. The belly, or that part of the body between the thorax and the pelvis. Also, the cavity of the belly, which is lined by the peritoneum, and contains the stomach, bowels, and other viscera. In man, often restricted to the part between the diaphragm and the commencement of the pelvis, the remainder being called the pelvic cavity.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.