A North American freshwater fish of the genus Lepomis (family Centrarchidae); specifically the common and widespread L. cyanellus, which has a greenish back and markings.
Origin
Late 19th century.
Definition of green sunfish in US English:
green sunfish
noun
A North American freshwater fish of the genus Lepomis (family Centrarchidae); specifically the common and widespread L. cyanellus, which has a greenish back and markings.