It is a wide waist sash, generally pleated worn with a tuxedo, or a single-breasted suit. Cummerbund wearers are seen on semi-formal or black tie party. It gives you a well dressed and sharp look. The contemporary use of the cummerbunds is purely artistic, while providing transition that divides and yet connect the shirt with the waistband. Cummerbunds are worn in many ways, depending on it’s styles and usage.
Stylish point of view : it gives your wardrobe a complete formal and sophisticated look. It is a component of semi-formal or black tie wear.
In the humorous point of view : it is commonly used to accommodate the expanding girth of gentlemen during large meal.
Military Cummerbunds: Cummerbunds is an accesory to the dress uniform used in Modern Indian and Pakistan army, used in ceremonial parades and dinners.
Scuba Diving : Cummerbunds are also an informal word used in scuba diving. It is described to be a wide waistband made out of a stout fabric back with velcro where a flexible rubber waistband helps to maintain watertight seal between jacket and pants of the suit.
To top it all the purpose is quite obvious, all are to connect your upper shirt to your trousers in a stylish, factual, and usable way.