kummerbund

noun1

1. •
   A broad sash, especially one that is pleated lengthwise and worn as an article of formal dress, as around a man's waist together with a tuxedo or dinner jacket.

   • Soon after the arrival of Mrs. Campbell, dinner was announced by Abboye. He came into the drawing room resplendent in his gold-and-white turban. […] His cummerbund matched the turban in gold lines. — 1927