Bivalvia bivalved • bivalvian · · · Info · Definitions · Characters · · Bivalvia · · Text Latin · · Script 8 · · Length Definitions · · · (noun) oysters; clams; scallops; mussels. Synonyms: class Bivalvia, Lamellibranchia, class Lamellibranchia, class Pelecypoda. · · Noun Definition 1 Characters · · B latin capital letter b U+0042 a latin small letter a U+0061 i latin small letter i U+0069 l latin small letter l U+006C v latin small letter v U+0076