Misbelieve is an uncommon word that means to hold a wrong or false belief. There are several synonyms that can be used in place of misbelieve. One option is to use the word misconceive, which means to form an incorrect or mistaken idea about something. Another synonym is misapprehend, which refers to a failure to understand something correctly. Misconstrue is another synonym that can be used, meaning to interpret something in the wrong way. Finally, misunderstand is a commonly used synonym for misbelieve, which refers to a lack of comprehension or knowledge about a particular topic or idea.