D defs.my
Entry 1 sense Webster, 1913

Prothorax

/prōth-ôr'-ăks/ · Pro·tho·rax · IPA /proʊθˈɔræks/
01 n. The first or anterior segment of the thorax in insects. See Illusts. of Butterfly and Coleoptera.
  1. 1.
    The first or anterior segment of the thorax in insects. See Illusts. of Butterfly and Coleoptera.(Zool.) See: Butterfly, Coleoptera