Source : Webster's Revised Unabridged Dictionary (1913)

Dibranchiate \Di*bran"chi*ate\, a. (Zo["o]l.)
   Having two gills. -- n. One of the Dibranchiata.

Source : WordNet®

dibranchiate
     n : cephalopods having two gills [syn: {dibranchiate mollusk}, {dibranch}]