The Collaborative International Dictionary of English v.0.48:
dibranch \dibranch\ n. a cephalopod having two gills; a member of the Dibranchiata. Syn: dibranchiate, dibranchiate mollusk. [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
dibranch n 1: cephalopods having two gills [syn: dibranchiate, dibranchiate mollusk, dibranch]