Muslim is THEIR term used to prevent them from saying their “beloved prophet’s” name. All other religions use their creator’s name - CHRISTianity, HINDUism, CONFUSISism, JUDEAism, etc. The correct term is then MOHAMMEDism and its adherents, MOHAMMEDans.
BTW, why are Mohammedans so adverse to mentioning the name of their “beloved prophet” when so many of them have the name Mohammed? But consistency and common sense are not traits normally found among them.