1. the middle region of the body of an arthropod between the head and the abdomen
2. the part of the human torso between the neck and the diaphragm or the corresponding part in other vertebrates
3. part of an insect's body that bears the wings and legs
4. The part of the trunk between the neck and the abdomen, containing that part of the body cavity the walls of which are supported by the dorsal vertebræ, the ribs, and the sternum, and which the heart and lungs are situated; the chest.