ENDOSKELETON

endoskeleton

(noun) the internal skeleton; bony and cartilaginous structure (especially of vertebrates)

Source: WordNet® 3.1

Etymology

Noun

endoskeleton (plural endoskeletons)

(anatomy) The internal skeleton of an animal, which in vertebrates is composed of bone and cartilage.

Source: Wiktionary

En`do*skel"e*ton, n. Etym: [Endo- + skeleton.] (Anat.)

Definition: The bony, cartilaginous, or other internal framework of an animal, as distinguished from the exoskeleton.

Source: Webster’s Unabridged Dictionary 1913 Edition