There are several synonyms for the word "orthodox" that can be used to express similar ideas with varying degrees of specificity. One common synonym is "traditional," which suggests that something is based on long-established beliefs or practices. Another synonym is "conventional," which implies adherence to accepted customs or standards. "Conservative" is also similar, but often carries connotations of resistance to change or reform. "Doctrinaire" suggests a rigid adherence to a particular ideology or set of principles. Finally, "dogmatic" can be used to describe someone who is uncompromising in their beliefs and opinions. Overall, these synonyms help capture the idea of adherence to established norms or principles.