The Collaborative International Dictionary of English v.0.48:

Pauperize \Pau"per*ize\, v. t. [imp. & p. p. Pauperized; p.
   pr. & vb. n. Pauperizing.]
   To reduce to pauperism; as, to pauperize the peasantry.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pauperize
    v 1: reduce to beggary [syn: beggar, pauperize, pauperise]