The term 'Sauce for Fish' can be summarized by three crossword solutions: TARTAR (6 letters), TARTARE (7 letters), and SOY (3 letters). TARTAR is a condiment made from capers, onions, and pickles mixed with mayonnaise. TARTARE is a French sauce made of mayonnaise, capers, and chopped onions. SOY sauce is a dark, salty liquid made from fermented soybeans. All three sauces are commonly used to enhance the flavor of fish dishes.