Lewis & Short

trādĭtor, ōris, m. [id] (post-Aug.).

  1. I. A betrayer, traitor, for the usual proditor: interfecto traditore, Tac. H. 4, 24; Sedul. Carm. 5, 61; Aug. Bapt. 7, 2.
  2. II. A teacher: alicujus scientiae, Arn. 3, 113; Tert. Coron. Mil. 4 fin.