Halibut

Halibut is the common name for three flatfish in the genera Hippoglossus and Reinhardtius from the family of right-eye flounders and, in some regions, and less commonly, other species of large flatfish. The word is derived from haly and butte (flat fish), for its popularity on Catholic holy days. Halibut are demersal fish and are highly regarded as a food fish as well as a sport fish.

Source: Wikipedia