Source : Webster's Revised Unabridged Dictionary (1913)

Duumvir \Du*um"vir\, n.; pl. E. {Duumvirs}, L. {Duumviri}. [L.,
   fr. duo two + vir man.] (Rom. Antiq.)
   One of two Roman officers or magistrates united in the same
   public functions.

Source : WordNet®

duumviri
     See {duumvir}