Entry 1 sense Webster, 1913 Lepidosauria /(-dō̇*sa̤"rĭ*ȧ)/ · Lep·i·do·sau·ri·a · IPA 01 n. pl. A division of reptiles, including the serpents and lizards; the Plagiotremata. 1. A division of reptiles, including the serpents and lizards; the Plagiotremata.(Zool.)