Obs. rare–1. [f. TRI- + Gr. ἀρχή beginning + -IST.] One who maintains the existence of three original principles of being.
1678. Cudworth, Intell. Syst., I. iv. § 13. 216. Plutarch was both a Triarchist and a Ditheist,—an assertor of Three Principles, but of Two Gods.
