1. uniformitarian - Noun
2. uniformitarian - Adjective
Of, pertaining to, or designating, the view or doctrine that existing causes, acting in the same manner and with essentially the same intensity as at the present time, are sufficient to account for all geological changes.
One who accepts uniformitarianism, or the uniformitarian doctrine.
Source: Webster's dictionaryThe catastrophist constructs theories, the uniformitarian demolishes them. William Whewell