Entry 1 sense Webster, 1913 Tepid /tĕp'ĭd/ · Tep·id · IPA /ˈtɛpɪd/ 01 a. Moderately warm; lukewarm; as, a tepid bath; tepid rays; tepid vapors. 1. Moderately warm; lukewarm; as, a tepid bath; tepid rays; tepid vapors.