Definition of: mustard

(mus′tərd) noun
1. Either of two species of Brassica, white mustard (B. hirta) and black mustard (B. nigra), both annual herbs with yellow flowers and pods of roundish seeds.
2. The pungent seed of the mustard, crushed and adapted for use as a condiment or as a medicinal rubefacient and diuretic.
3. A strong, dark-yellow color, the color of ground mustard. [<OF moustarde <L mustum must³; from once having been prepared with must]