D defs.my
Entry 1 sense Webster, 1913

Sea urchin

/sēʹ ûr'tsĭn/ · Sea· ur·chin · IPA /ˈsi ˌɝtʃɪ̈n/
01 Any one of numerous species of echinoderms of the order Echinoidea.
  1. 1.
    Any one of numerous species of echinoderms of the order Echinoidea.(Zool.)