ETYM Latin abdomen (a word of uncertain etymol.): cf. French abdomen.
The region of the body of a vertebrate between the thorax and the pelvis; SYN. venter, stomach, belly.
In vertebrates, the part of the body below the thorax, containing the digestive organs; in insects and other arthropods, it is the hind part of the body. In mammals, the abdomen is separated from the thorax by the diaphragm, a sheet of muscular tissue; in arthropods, commonly by a narrow constriction. The female reproductive organs are in the abdomen. In insects and spiders, it is characterized by the absence of limbs.