Definition that contains nudibranch
- nudibranch any of various marine gastropods of the suborder Nudibranchia having a shell-less and often beautifully colored body
- sea slug any of various marine gastropods of the suborder Nudibranchia having a shell-less and often beautifully colored body
- ceras one of the often brightly colored and branching hornlike structures on the back of the nudibranch (and other related mollusks) that serve as gills