Lewis & Short

prŏbātor, ōris, m. [probo],

  1. I. an approver (rare but class.): quid interest inter suasorem facti et probatorem? Cic. Phil. 2, 12, 29: rationis, id. Caecin. 29, 85: ingenii, Ov. P. 2, 2, 106: malorum improbator, bonorum probator, App. de Deo Socr. 16.
  2. II. A trier, examiner (eccl. Lat.), Vulg. Jer. 20, 12.