n., pl., tho·rax·es, or tho·ra·ces (thôr'ə-sēz', thōr'-).
- The part of the human body between the neck and the diaphragm, partially encased by the ribs and containing the heart and lungs; the chest.
- A part in other vertebrates that corresponds to the human thorax.
- The second or middle region of the body of an arthropod, between the head and the abdomen, in insects bearing the true legs and wings.
[Middle English, from Latin thōrāx, breastplate, chest, from Greek.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
