n. 芥子泥

[医] 芥子泥, 芥子硬膏

[ noun ]
a plaster containing powdered black mustard; applied to the skin as a counterirritant or rubefacient
<noun.artifact>

Sinapism \Sin"a*pism\, n. [L. sinapismus, Gr. ????, the use of a
mustard blister, fr. ??? to apply a mustard blister, fr. ????
mustard.] (Med.)
A plaster or poultice composed principally of powdered
mustard seed, or containing the volatile oil of mustard seed.
It is a powerful irritant.