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.]WordNet (r) 3.0 (2006):
cummerbund n 1: a broad pleated sash worn as formal dress with a tuxedo