noun.
A plant of the genus Brassica, formerly classed as Sinapis.
noun.
The seed of mustard crushed and sifted (and often adulterated), used in the form of a paste as a condiment. or, in the form of a poultice (sinapism), plaster, or prepared paper (mustard-paper), as a rubefacient.
noun.
One of numerous mustard-like plants, almost all cruciferous: used with a qualifying word. See names below
noun.
Clypeola Jonthlaspi.
noun.
Sometimes, erroneously, the pennycress