'Diarchy' definitions:

Definition of 'diarchy'

From: WordNet
noun
A form of government having two joint rulers [syn: diarchy, dyarchy]

Definition of 'Diarchy'

From: GCIDE
  • Diarchy \Di"arch*y\, n. [Gr. di- = di`s- twice + ? to rule.] A form of government in which the supreme power is vested in two persons. Diarial