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.
obi
noun
A sash worn with a kimono.
A strip of paper looped around a book or other product.
How often have the words cummerbund and obi occurred in a corpus of books? (source: Google Ngram Viewer )