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).

Of a dark yellow colour.

plural of mustard

(archaic) The medicinal use of mustard plasters.

Flavoured or topped with mustard.

A surname.

plural of Mustard

(historical) A manufacturer of mustard.

plural of mustarder

(transitive, historical) To affect with mustard gas, (as in World War I). To gas.