Either of two dolphins of the genus Lagenorhynchus having conspicuous white sides, L. acutus of the North Atlantic, and L. obliquidens of the North Pacific.
Origin
Mid 19th century.
Definition of white-sided dolphin in US English:
white-sided dolphin
noun
Either of two dolphins of the genus Lagenorhynchus having conspicuous white sides, L. acutus of the North Atlantic, and L. obliquidens of the North Pacific.