large flounder
Refers to a large flounder, specifically the species Paralichthys olivaceus or similar large flatfish. The name literally means 'door-board flounder', likely from its flat, broad shape. Used in culinary and fishing contexts.
See also: ヒラメ
I found a large flounder at the market.
Large flounder is delicious when made into sashimi.
平目 is the general term for flounder or flatfish, while 戸板平目 specifically refers to a large flounder, often the same species but emphasizing size.
Compound of 戸板 (door board) and 平目 (flounder), likely referring to the fish's large, flat, board-like shape. The exact origin is uncertain, but the name is descriptive.