Definition of opisthobranch
: any of a subclass (Opisthobranchia) of marine gastropod mollusks that have the gills when present posterior to the heart and often lack a shell
Origin of opisthobranch
New Latin Opisthobranchia, from Greek opisthen behind (akin to Greek epi on) + branchia gills — more at epi-
First Known Use: circa 1856
Learn More about opisthobranch
Britannica.com: Encyclopedia article about "opisthobranch"
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