Pronunciation: (u-pis'thu-brangk"), [key]
any gastropod mollusk of the order Opisthobranchia, as the sea slugs, sea butterflies, and sea hares, characterized by a vestigial or absent mantle and shell and two pairs of tentacles.
of or pertaining to the opisthobranches. Also,o•pis•tho•bran•chi•atePronunciation: (u-pis"thu-brang'kē-it, -āt"). [key]
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.