The Collaborative International Dictionary of English v.0.48:

Predispose \Pre`dis*pose"\, v. t. [imp. & p. p. Predisposed;
   p. pr. & vb. n. Predisposing.] [Pref. pre- + dispose: cf.
   F. pr['e]disposer.]
   1. To dispose or incline beforehand; to give a predisposition
      or bias to; as, to predispose the mind to friendship.
      [1913 Webster]

   2. To make fit or susceptible beforehand; to give a tendency
      to; as, debility predisposes the body to disease.
      [1913 Webster]

   Predisposing causes (Med.), causes which render the body
      liable to disease; predisponent causes.
      [1913 Webster]

WordNet (r) 3.0 (2006):

predispose
    v 1: make susceptible; "This illness predisposes you to gain
         weight"

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "predispose":
   affect, bend, bias, color, dispose, impress, incline, induce,
   influence, lead, move, persuade, prompt, soften up, strike, sway,
   tinge, tone, wear down, weigh with, work