mesosternum
/ˌmɛsə(ʊ)ˈstəːnəm/noun
1 Entomology. The sternum of the mesothorax of an insect or (especially formerly) an equivalent or associated part. Also (in Zoology ): the middle plate of the sternum in brachyuran crabs.
2 Anatomy and Zoology. The body of the sternum, situated between the manubrium and the xiphisternum.
Origin
Early 19th century; earliest use found in William Kirby (1759–1850), entomologist and naturalist. From meso- + sternum.