The Collaborative International Dictionary of English v.0.48:

Refracting \Re*fract"ing\, a.
   Serving or tending to refract; as, a refracting medium.
   [1913 Webster]

   Refracting angle of a prism (Opt.), the angle of a
      triangular prism included between the two sides through
      which the refracted beam passes in the decomposition of
      light.

   Refracting telescope. (Opt.) See under Telescope.
      [1913 Webster]

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]