Lewis & Short

2. actŭārĭus, ĭi (written by some actarius, to distinguish it from the preceding, Vel. Long. 2234 P., and so found in Inscr. Grut. 260; ap. Henzen, 6284), sc. scriba, m. [2. actus, II. B. 1.].

  1. I. A short-hand writer, Suet. Caes. 55; Sen. Ep. 33, 9; cf. Lips. Tac. Ann. 5, 4.
  2. II. One who writes out accounts, Petr. 53.