The Collaborative International Dictionary of English v.0.48:

Impatronize \Im*pat"ron*ize\, v. t. [imp. & p. p.
   Impatronized; p. pr. & vb. n. Impatronizing.]
   To make lord or master; as, to impatronize one's self of a
   seigniory. [R.] --Bacon.
   [1913 Webster]