Sauce
From the Simple English Wikipedia, the free encyclopedia that anyone can change
Sauce is a hot or a cold liquid that is added to another food to add flavor to it. Sauces are not eaten by themselves, they are always added to another dish. A sauce can be something simple, like liquid butter or something fancier like a sauce with cream and ham (called Carbonara) or with ground meat (called Bolognese), or even with herbs and garlic (called Pesto).
An example would be a tomato-based sauce that is usually poured over spaghetti before it is eaten.