A sauce usually composed of yolks of eggs beaten with olive oil until thick, and seasoned with vinegar, or lemon juice, salt, pepper, or other ingredients. Commonly used as a sandwich condiment or as a salad dressing. Popular brand names include Miracle Whip and Hellman's. Mayonnaise is considered a fairly mild condiment, but a good sauce can add a lot of flavor to a sandwich, a burger, or a pasta salad.