cummerbund

from WordNet (r) 3.0 (2006)

cummerbund
    n 1: a broad pleated sash worn as formal dress with a tuxedo

from The Collaborative International Dictionary of English v.0.48

Cummerbund \Cum"mer*bund`\, n. [Written also {kummerbund},
   {cummerband}, etc.] [Hind. kamarband, fr. Per. Kamar loins +
   band fastening.]
   A sash for the waist; a girdle. [India]
   [Webster 1913 Suppl.]