ab·do·men 
(ăbdə-mən)
(ăbdə-mən)n.
1. The part of the body that lies between the thorax and the pelvis and encloses the stomach, intestines, liver, spleen, and pancreas in humans and other mammals. Also called belly.
2. The corresponding region in vertebrates other than mammals.
3. The posterior segment of the body in arthropods.
[Latin abdōmen, belly; see dhē- in the Appendix of Indo-European roots.]