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

The whole, ground, cracked, or bruised mustard seeds are mixed with water, vinegar, lemon juice, wine, or other liquids, salt, and often other flavourings and spices, to create a paste or sauce ranging in colour from bright yellow to dark brown. The taste of mustard ranges from sweet to spicy.