Ridge-like ingrowth of the exoskeleton of an arthropod that supports internal organs and provides attachment points for muscles

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Apodeme \Ap"o*deme\, n. [Pref. apo- + Gr. ? body.] (Zo["o]l.) One of the processes of the shell which project inwards and unite with one another, in the thorax of many Crustacea. [1913 Webster] ||

Wiktionary Word definitions in Wiktionary
n. (context anatomy English) An ingrowth of the arthropod exoskeleton, serving as an attachment site for muscles.

WordNet Word definitions in WordNet
n. ridge-like ingrowth of the exoskeleton of an arthropod that supports internal organs and provides attachment points for muscles