What is Monistic?

Monistic definition and meaning on Dictionary terms:
Philosophy. (in metaphysics) any of various theories holding that there is only one basic substance or principle as the ground of reality, or that reality consists of a single element.Compare dualism(def 2), pluralism(def 1a). (in epistemology) a theory that the object and datum of cognition are identical.Compare pluralism(def 1b).

the reduction of all processes, structures, concepts, etc., to a single governing principle; the theoretical explanation of everything in terms of one principle.
the conception that there is one causal factor in history; the notion of a single element as primary determinant of behavior, social action, or institutional relations.