Borrowed from English cummerbund, from Hindustani کمر بند / कमरबंद (kamarband), from Classical Persian کمربند (kamarband), derived from کمر (kamar, “waist”) + بند (band, “band”).
The English -u- (instead of more etymological -a-) is a pronunciation spelling representing Hindi . In German, in turn, this -u- was given a spelling pronunciation, leading to as well as a remotivation as Kummer (“sorrow”) + Bund (“waistband”). German Bund is indeed related with Persian بند (band) through Proto-Indo-European.
Kummerbund m (strong, genitive Kummerbundes or Kummerbunds, plural Kummerbunde)
| singular | plural | ||||
|---|---|---|---|---|---|
| indef. | def. | noun | def. | noun | |
| nominative | ein | der | Kummerbund | die | Kummerbunde |
| genitive | eines | des | Kummerbundes, Kummerbunds | der | Kummerbunde |
| dative | einem | dem | Kummerbund, Kummerbunde1 | den | Kummerbunden |
| accusative | einen | den | Kummerbund | die | Kummerbunde |
1Now rare, see notes.