Fundamentalist (noun)

1. A person who adheres to the fundamentals of a particular religion or ideology and is unwilling to consider other beliefs or perspectives.
2. A person who adheres to traditional or conservative views and is unwilling to consider new or progressive ideas.

Origin:

From fundamental + -ist, coined in 1920s in reference to a group of protestants who believe in the inerrancy of the bible and who emphasize the literal interpretation of its teachings.

Examples:

1. The religious fundamentalist refused to accept any interpretation of the Bible that deviated from his own.
2. The political fundamentalist refused to consider any policies that did not align with his conservative views.
3. The group of fundamentalists were known for their strict adherence to traditional religious beliefs.
4. The conservative movement had many fundamentalists who were unwilling to accept any progressive change.
5. The Muslim fundamentalist group advocated for the strict implementation of sharia law.