Sin'a-pīzm, n.

n. [Fr. sinapisme, Sp. sinapismo, It. sinapismo, senapismo, Lat. sinapismus, Gr. σιναπισμός, from σιναπίζειν, to apply a mustard blister, fr. σίναπι, σίναπι, Lat. sinapi, sinapis, mustard; A-S. senepe, O. H. Ger. senaf, N. H. Ger. senf.] (Med.) A cataplasm composed of mustard seed pulverized, with some other ingredients, and used as an external application. It is a powerful irritant.