ˈthōrˌaks, -ȯr- noun
( plural thoraxes -sə̇z ; or tho·ra·ces ˈthōrəˌsēz, -ȯr also thəˈrāˌs-)
Etymology: Middle English, from Latin, corslet, chest, from Greek thōrax; perhaps akin to Sanskrit dhārayati he holds, carries, keeps — more at firm
1. : the part of the body of man and other mammals situated between the neck and the abdomen and supported by the ribs, costal cartilages, and sternum ; also : thoracic cavity
2.
[New Latin, from Latin]
a. : a portion of the insect body that is the middle of the three chief divisions of the body and that consists of three segments each commonly bearing a pair of legs and the last two each usually bearing a pair of wings in the adult
b. : the corresponding part of a crustacean or arachnid usually fused with the head to form a cephalothorax
c. : the anterior division of the body of a zooid of a compound ascidian comprising the branchial sac and surrounding atrium
d. : an anterior differentiated part of the body behind the head of many tubicolous polychaete worms
3. : breastplate , cuirass , corslet ; especially : the breastplate worn by the ancient Greeks