Kermesite is a mineral consisting of antimony sulfide. The word "kermesite" is quite specific, so there aren't many synonyms that would be applicable for it. However, there are a few terms that can be used to refer to antimony sulfide in general. They include the words stibnite, antimonite, and antimony glance. These terms can be used interchangeably with the word "kermesite" in certain contexts, particularly when discussing minerals or geology. It's important to keep in mind that while these terms are related, they do not always refer to the same exact mineral or compound.