ˈstərnəm, ˈstə̄n-, ˈstəin- noun
( plural sternums -mz ; or ster·na -nə)
Etymology: New Latin, from Greek sternon breast, chest, breastbone; akin to Old High German stirna forehead, Sanskrit stīrna spread, strewn, Latin sternere to spread out — more at strew
1. : a bone or cartilage or a series of more or less distinct bony or cartilaginous segments lying in the median ventral part of the body of most vertebrates above fishes, connecting with the ribs or the shoulder girdle or with both, being in man about seven inches long, consisting in the adult of three parts, connecting with the clavicles and the cartilages of the upper seven pairs of ribs, and being in birds modified into a single broad bony plate that usually bears a high median keel for the attachment of the wing muscles : breastbone — see bat illustration
2.
a. : the ventral part of a somite of an arthropod
b. : the whole ventral wall of the arthropod thorax