Lewis & Short

calcŭlātor, ōris, m. [calculo],

  1. I. a computer, teacher of arithmetic, = λογιστής (post-Aug.), Mart. 10, 62, 4; Acron. ad Hor. S. 1, 6. 72; Isid. Orig. 1, 3, 1; cf. id. ib. 1, 10, 43.
  2. II. A book-keeper, accountant, Dig. 38, 1, 7, § 5; 27, 1, 15, § 5.