‖n.; pl. Epimera [ NL., fr. Gr. 'epi` upon + &unr_; a part. ] (Zoöl.) (a) In crustaceans: The part of the side of a somite external to the basal joint of each appendage. See Illust. under Crustacea. (b) In insects: The lateral piece behind the episternum. [ Written also epimerum. ] [ 1913 Webster ]