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Webster 1913 Edition

Noun.

[L.

duumviratus

, fr.

duumvir

The union of two men in the same office; or the office, dignity, or government of two men thus associated, as in ancient Rome.

Noun.

The union of two men in the same office; or the office, dignity or government of two men thus associated; as in ancient Rome.

duumvirate ‎(plural duumvirates)

Any of several branches of the executive in Republican Rome controlled by two people.
A group of two officials; a union or coalition of two people.
- 1977, Alistair Horne, A Savage War of Peace, New York Review Books 2006, p. 310:
  To replace the all-powerful Salan, de Gaulle appointed a duumvirate – Paul Delouvrier and General Maurice Challe.
- 2002, Colin Jones, The Great Nation, Penguin 2003, p. 241:
  This was to raise the prospect of a duumvirate – ‘two heads in the same hat’, as Bernis quaintly put it.

branche of the executive in Republican Rome controlled by two people