The Collaborative International Dictionary of English v.0.48:

Refract \Re*fract"\ (r?*fr$kt"), v. t. [imp. & p. p.
   Refracted; p. pr. & vb. n. Refracting.] [L. refractus, p.
   p. of refringere; pref. re- re- + frangere to break: cf. F.
   r['e]fracter. SEe FRacture, and cf. Refrain, n.]
   1. To bend sharply and abruptly back; to break off.
      [1913 Webster]

   2. To break the natural course of, as rays of light orr heat,
      when passing from one transparent medium to another of
      different density; to cause to deviate from a direct
      course by an action distinct from reflection; as, a dense
      medium refrcts the rays of light as they pass into it from
      a rare medium.
      [1913 Webster]

WordNet (r) 3.0 (2006):

refract
    v 1: subject to refraction; "refract a light beam"
    2: determine the refracting power of (a lens)

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "refract":
   bend, bias, crook, curve, deflect, deviate, diffract, diffuse,
   disperse, distort, diverge, divert, dogleg, hairpin, pull, scatter,
   skew, turn, twist, warp, zigzag