The term "flotsam-jetsam" is often used to describe debris or unwanted materials floating on the surface of water. It has become a common phrase in popular culture, but there are various synonyms that can be used instead. Some of these include detritus, refuse, debris, waste, and rubbish. These words can be used interchangeably to describe any unwanted materials floating on the surface of water, or even to describe clutter or unwanted items in a different context. It's important to have a diverse vocabulary, and using synonyms instead of relying on the same words repeatedly can add variety to your writing and communication.