Webster's Revised Unabridged Dictionary · 1913

Flatfish

Flatfish , noun

(Zoology) Any fish of the family Pleuronectida; esp., the winter flounder (Pleuronectes Americanus). The flatfishes have the body flattened, swim on the side, and have eyes on one side, as the flounder, turbot, and halibut. See Flounder.