Definition of "mustard"

A plant of certain species of the genus Brassica, or of related genera (especially Sinapis alba, in the family Brassicaceae, with yellow flowers, and linear seed pods).  examples

Powder or paste made from seeds of the mustard plant, and used as a condiment or a spice.  examples

The leaves of the mustard plant, used as a salad.  examples

Dark yellow colour, the colour of mustard.  examples

One of a family of vesicants containing one or more 2-chloroethyl (C2H4Cl) groups, commonly used in chemical warfare and cancer chemotherapy.  examples

The tomalley of a crab, which resembles the condiment.  examples

Of a dark yellow colour.  quotations  examples