Butter sauce is a rich and creamy condiment that is often used as a topping or a base for a variety of dishes. It is made by melting butter and combining it with herbs, spices, or other ingredients to create a flavorful sauce. Some synonyms for butter sauce include beurre blanc, hollandaise sauce, and meuniere sauce. Beurre blanc is a French sauce made with white wine, shallots, and butter, while hollandaise sauce is a classic French sauce made with egg yolks, lemon juice, and butter. Meuniere sauce is a French sauce made with brown butter, lemon juice, and parsley, and it is commonly used with fish dishes.