'Prothorax' definitions:

Definition of 'prothorax'

(from WordNet)
noun
The anterior part of an insect's thorax; bears the first pair of legs

Definition of 'Prothorax'

From: GCIDE
  • Prothorax \Pro*tho"rax\, n. [Pref. pro- + thorax.] (Zool.) The first or anterior segment of the thorax in insects. See Illusts. of Butterfly and Coleoptera. [1913 Webster]