white mustard
an annual mustard (Brassica hirta) that has seeds which are ground and made into a paste used as a condiment
white mustard
noun
An annual Eurasian plant (Sinapis alba syn. Brassica alba) in the mustard family, having yellow flowers and yellowish-brown seeds used as a spice and for their oil. Also called yellow mustard.
Origin of white mustard
From the relatively light color of the seeds when compared to those of black mustard.