fillet or filet means: It is necessary to remove the bones of a fish so that there remains only the flesh. It depends on what type of fish you are trying to remove. It is not the same for all fish. For example, a flat fish like a flounder will require different techniques than a round fish like a trout. You can learn the best ways to cook by reading a book or watching cooking programs. Your seafood merchant will help you if in doubt. (in Cooking Dictionary)