Source : Webster's Revised Unabridged Dictionary (1913)

Directorate \Di*rect"o*rate\, n. [Cf. F. directorat.]
   The office of director; also, a body of directors taken
   jointly.

Source : WordNet®

directorate
     n : a group of persons chosen to govern the affairs of a
         corporation or other large institution [syn: {board of
         directors}]