1. a mustard plaster applied to the skin as a medical treatment to relieve pain or inflammation
Usage: medical; archaic

Examples

• The doctor applied a sinapism to the patient’s chest to treat bronchitis.
• In the 19th century, sinapisms were commonly used for respiratory ailments.
• The nurse prepared a sinapism using mustard powder and flour.
• His grandmother swore by sinapisms for treating muscle aches.
• The medical text described how to properly apply a sinapism to avoid skin burns.