Entry 1 sense Webster, 1913 Endolymphatic · En·do·lym·phat·ic · IPA /ˌɛn.də.lɪmˈfæt.ɪk/ 01 a. Pertaining to, or containing, endolymph; as, the endolymphatic duct. 1. Pertaining to, or containing, endolymph; as, the endolymphatic duct.(Anat.)