Mustard is a condiment made from the seeds of a mustard plant (white or yellow mustard, Sinapis alba; brown or Indian mustard, Brassica juncea; or black mustard, B. nigra).

The whole, ground, cracked, or bruised mustard seeds are mixed with water, salt, lemon juice, or other liquids, and sometimes other flavorings and spices, to create a paste or sauce ranging in color from bright yellow to dark brown. The tastes range from sweet to spicy.