Entry 1 sense Webster, 1913 Ischiocerite · Is·chi·o·ce·rite · IPA /ˌɪskiəʊˈsɪəɹaɪt/ 01 n. The third joint or the antennæ of the Crustacea. 1. The third joint or the antennæ of the Crustacea.(Zool.)