A halibut found in the Atlantic; specifically Hippoglossus hippoglossus, which is found in temperate waters of the North Atlantic and can grow to an exceptionally large size.
Origin
Late 19th century.
Definition of Atlantic halibut in US English:
Atlantic halibut
noun
A halibut found in the Atlantic; specifically Hippoglossus hippoglossus, which is found in temperate waters of the North Atlantic and can grow to an exceptionally large size.