substance added to food to enhance its flavor

A condiment is a prepared food that is put to other food, to make the food better or taste different. It usually is in the form of a sauce or a powder. Salt and pepper are examples of well-known condiments. Ketchup, mustard, relish, mayonnaise, horseradish, soy sauce and Worcestershire sauce are also well-known condiments.

The mustard plant
Mustard is a well-known condiment.