IPA: /ˈtraɪ.əm.vɪr/
KK: /ˈtraɪəmˌvɪr/
A member of a group of three individuals who share power or authority, especially in a political context.
In ancient Rome, a triumvir was part of a powerful trio that governed the state.
Triumvir is formed from "tri-" (meaning three) and "vir" (meaning man). The term originally referred to a group of three men, particularly in a political context, such as the Roman Triumvirate, which was a political alliance of three powerful individuals.
Think of 'three' ('tri-') men ('vir') working together — that's what a triumvir is.
No commonly confused words.