An assessment of the meaning and role of uniformitarianism in natural history is demanded by: (1) the confusion it has generated for nearly two centuries, (2) the recent revolution in geology that has rejected traditional uniformitarianism in favor of neocatastrophism, and (3) the accusation by some who embrace neocatastrophism that diluvialists—failing to understand nuances of uniformitarianism—argue futilely against the straw man of Lyellian gradualism. The first level of this much-needed assessment focuses on the semantic confusion, which is significant. Some suggest that identifying four distinct definitions of "uniformitarianism" resolves all problems. However this scheme does not go far enough: though it helps clarify the issue, it is no solution. I propose a more radical step of eliminating unnecessary terms to advance conceptual clarity. Of the nine terms associated with uniformitarianism, seven can be replaced or eliminated. This proposal refutes the accusation that diluvialists do not understand uniformitarianism, showing rather that it is the accusers who misunderstand key concepts about earth's past.