cummerbund
broad waist sash, usually pleated, which is often worn with single-breasted dinner jackets or tuxedos
en-US/ˈkʌmɚˌbʌnd/
en-GB/ˈkʌməˌbʌnd/
broad waist sash, usually pleated, which is often worn with single-breasted dinner jackets or tuxedos