uniformitarian

adjective

1. supporting, conforming to, or derived from a theory or doctrine about uniformity, especially on the subject of geology.
2. Geology. of or relating to the thesis that processes that operated in the remote geological past are not different from those observed now.

noun

3. a person who accepts or supports a uniformitarian theory.

adjective

1. of or relating to uniformitarianism
2. of, characterized by, or conforming to uniformity

noun

3. a supporter of a theory of uniformity or of uniformitarianism