A yellow or brown paste or powder made from the seeds of a mustard plant, used as a condiment or spice. She added a dollop of mustard to her sandwich for extra flavor.
A plant of the genus Brassica, whose seeds are used to make mustard condiment. The farmer grew mustard in his fields for both its seeds and its greens.
A dark yellow color, similar to the color of mustard condiment. She wore a mustard-colored sweater that brightened up her outfit.
(military, informal) Sulfur mustard; a blistering chemical warfare agent also known as mustard gas. The soldiers reported a faint garlic odor, a tell-tale sign of mustard in the air.