Entry 1 sense Webster, 1913 Endognath /(ĕn"dŏg*năth)/ · En·dog·nath · IPA 01 n. The inner or principal branch of the oral appendages of Crustacea. See Maxilla. 1. The inner or principal branch of the oral appendages of Crustacea. See Maxilla.(Zoöl.) See: Maxilla