English sole

Also called lemon sole in the United States, this species of flounder is low in fat and finely textured. It ranges from 1⁄4 to 2 pounds and can be purchased whole or in fillets. It's often labeled simply as "fillet of sole." English sole can be prepared in a variety of ways including baking, broiling, poaching and sautéing. See also fish.

The noun has 2 meanings:

Meaning #1: highly valued almost pure white flesh
  Synonym: lemon sole

Meaning #2: popular pale brown food flatfish of the Pacific coast of North America
  Synonyms: lemon sole, Parophrys vitulus