There are many different synonyms for the word "overreligious" that can be used depending on the context of the sentence. A few common ones include "fanatical", "zealous", "extreme", and "excessive". Other possible synonyms might include "dogmatic", "narrow-minded", "fundamentalist", and "devout". Some words that are more positive in tone might include "committed", "pious", and "devoted", though these terms may not always convey the negative connotations often associated with being "overreligious". In any case, it is important to choose the right synonym that captures the intended meaning of the word in the specific context in which it is being used.