Dictionary entry

Sinapism

Webster's Dictionary 1913

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.