Thō'rax, n.

(89), n. [Lat., from Gr. θώραξ.]

1. (Anat.) The portion of the trunk between the neck and abdomen, the cavity of which, bounded by the spinal column, the ribs with their cartilages, and the sternum, and below by the diaphragm, is occupied mainly by the lungs and heart; the chest.
2. (Entom.) The second general segment of insects; that part of the body between the head and the abdomen.
3. A breastplate, cuirass, or corset.