What is another word for Doctrinarian?
Pronunciation: [dˌɒktɹɪnˈe͡əɹi͡ən] (IPA) 
The term doctrinarian refers to a person who is strictly adherent to a particular doctrine or set of beliefs. Some synonyms for this word could be dogmatic, rigid, inflexible, uncompromising, unyielding, or orthodox. All of these words carry connotations of someone who is firm in their beliefs and unwilling to consider alternative perspectives. Other possible synonyms could include fundamentalist, purist, zealot, or ideologue. Each of these words suggests a focus on a particular ideology or set of principles and a determination to uphold them at all costs. Ultimately, the choice of synonym will depend on the specific context in which the word is being used.
