Lewis & Short

dictātūra, ae, f. [dictator].

  1. I. The office of a dictator, dictatorship, Cic. Phil. 1, 1 fin.; id. Off. 3, 31, 112; * Caes. B. C. 3, 2; Liv. 6, 39; 7, 3 fin.; Quint. 3, 8, 53; Suet. Caes. 76; id. Aug. 52 et saep.
  2. * II. The work of dictating to pupils; only in a play upon the double meaning in the sentence: Sullam nescisse litteras, qui dictaturam deposuerit, Caes. ap. Suet. Caes. 77.