Cummerbund

noun

1. A broad sash, especially one that is pleated lengthwise and worn as an article of formal dress, as with a dinner jacket.
2. A shawl, or large and loose sash, worn as a belt.
3. A sash for the waist; a girdle.
4. A broad sash, especially one that is pleated lengthwise and worn as an article of formal dress, as with a tuxedo or dinner jacket.
5. a broad pleated sash worn as formal dress with a tuxedo