- of, in, on, or for the abdomen: abdominal wall; abdominal pains.
- Usually abdominals. Informal. the abdominal muscles.
1550s, from medical Latin abdominalis, from abdomen (genitive abdominis); see abdomen.
- In vertebrates, the portion of the body between the thorax and pelvis, containing the stomach, intestines, liver, and other organs. In mammals, the abdomen is separated from the thorax by the diaphragm.
- In arthropods, the last, most posterior segment of the body.