Entry 1 sense Webster, 1913 Teratoid · Ter·a·toid · IPA /ˈtɛɹ.ə.tɔɪd/ 01 a. Resembling a monster; abnormal; of a pathological growth, exceedingly complex or highly organized. 1. Resembling a monster; abnormal; of a pathological growth, exceedingly complex or highly organized.