Lewis & Short

trĭumvĭrātus, ūs, m. [triumviri], the office or dignity of a triumvir, the triumvirate: triumviratus (coloniae deducendae), * Cic. Brut. 31, 117; cf.: tribunatu ante gesto triumviratibusque, Liv. 9, 46, 3: ne triumviratu suo (reipublicae constituendae) nimis superbiat Antonius, Plin. 9, 35, 59, § 122: nullo more triumviratus invaditur, Flor. 4, 6, 3: reipublicae constituendae, Suet. Aug. 27: senatūs legendi, id. ib. 37.