halibut

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several large edible flatfishes of the genus Hippoglossus and related genera, of northern Atlantic or Pacific waters.

Century Dictionary and Cyclopedia

1. n. A fish of the genus Hippoglossus, H. vulgaris, and the largest species of the flatfish family or Pleuronectidæ. This fish has a compressed body, one side being colored, the other white, and both eyes on the same side of the head. It grows to a great size, sometimes weighing from 300 to 400 pounds. It forms an article of food, and some parts of the body are fat, tender, and delicious. The name is also given to various other species of Pleuronectidæ, such as Reinhardtius hippoglossoides, known as the Greenland halibut, and Paralichthys californicus, known in California as the Monterey halibut and bastard halibut.

Wiktionary

1. n. A large flatfish of the genus Hippoglossus, which sometimes leaves the ocean floor and swims vertically.

GNU Webster's 1913

1. n. (Zoöl.) A large, northern, marine flatfish (Hippoglossus vulgaris), of the family Pleuronectidæ. It often grows very large, weighing more than three hundred pounds. It is an important food fish.

WordNet 3.0

1. n. marine food fish of the northern Atlantic or northern Pacific; the largest flatfish and one of the largest teleost fishes
2. n. lean flesh of very large flatfish of Atlantic or Pacific