A cummerbund is a pleated sash that is worn around the waist with a dinner jacket or a tuxedo. It is considered formal wear and is often worn at black-tie events, ceremonial occasions, proms and weddings. When worn by men, the cummerbund usually matches the man's bow tie.
The cummerbund was first worn by British officers in India during colonial times. It provided the officers with an alternative to the waistcoat (also known as a vest). The garment became popular with civilians and was worn during the summer months with a dinner jacket.
The word cummerbund has Persian origins, and the word kamarband in Persian today refers to any piece of clothing that is like a belt.