Sinapism

n.

1.

(Med.) A plaster or poultice composed principally of powdered mustard seed, or containing the volatile oil of mustard seed. It is a powerful irritant.

Noun

1.

sinapism - a plaster containing powdered black mustard; applied to the skin as a counterirritant or rubefacient Synonyms: mustard plaster

cataplasm, mustard plaster, plaster, poultice