Cummerbund definition

From Hindustani कमरबन्द / (kamar-band) < (kamar-band); (kamar = waist) + (band = band) meaning "waistband", or "belt".

A broad sash, especially one that is pleated lengthwise and worn as an article of formal dress, as with a tuxedo or dinner jacket.

The thin boys with their brush cuts and spotty faces, their dinner jackets and burgundy cummerbunds with matching bow ties, would gape at us. - Edmund White, "My Women" http://www.newyorker.com/fact/content/articles/050613fa_fact