The Collaborative International Dictionary of English v.0.48:

Redemptorist \Re*demp"tor*ist\ (-t?r*?st), n. [F.
   r['e]demptoriste, fr. L. redemptor redeemer, from redinere.
   See Redeem.] (R.C.Ch.)
   One of the Congregation of the Most Holy Redeemer, founded in
   Naples in 1732 by St. Alphonsus Maria de Liquori. It was
   introduced onto the United States in 1832 at Detroit. The
   Fathers of the Congregation devote themselves to preaching to
   the neglected, esp. in missions and retreats, and are
   forbidden by their rule to engage in the instruction of
   youth.
   [1913 Webster]