n. The office or magistracy of a triumvir, specifically of one of the ancient Roman groups of triumviri.n. Government by three men in coalition.n. A group of three men in office or authority; specifically, in Roman history, either the coalition (First Triumvirate) between Pompey, Julius Cæsar, and Crassus, 60 b. c., which controlled the Roman world for several years, or that (Second Triumvirate) between Mark Antony, Octavian (Augustus), and Lepidus, 43 b. c., which overthrew the republican party and ordered the second proscription.n. A party of three men; three men or three personifications in company or forming one group; also, a trio or triad of any kind.