Lewis & Short

purgātor, ōris, m. [purgo].

  1. I. Lit., a cleanser, purger (post-class.): cloacarum, Firm. Math. 8, 20: ferarum, an exterminator of wild beasts, App. Mag. p. 288, 26.
  2. II. Trop.: animae, Aug. Civ. Dei, 10, 10.