branchiae branchia • branchial · · · Info · Definitions · Synonyms · Characters · · branchiae · · Text Latin · · Script 9 · · Length Definitions · · · (noun) respiratory organ of aquatic animals that breathe oxygen dissolved in water. Synonyms: gill, branchia. · · Noun Definition 1 Synonyms · · · gill · · Synonym 1 branchia · · Synonym 2 Characters · · a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E r latin small letter r U+0072