refraction Meaning, Definition & Usage

  1. noun the change in direction of a propagating wave (light or sound) when passing from one medium to another
  2. noun the amount by which a propagating wave is bent
    deflexion; deflection.

WordNet

Re*frac"tion noun
Etymology
F. réfraction.
Definitions
  1. The act of refracting, or the state of being refracted.
  2. The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a different density from that through which it has previously moved.
    Refraction out of the rarer medium into the denser, is made towards the perpendicular. Sir I. Newton.
  3. (Astron.) (a) The change in the direction of a ray of light, and, consequently, in the apparent position of a heavenly body from which it emanates, arising from its passage through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction. (b) The correction which is to be deducted from the apparent altitude of a heavenly body on account of atmospheric refraction, in order to obtain the true altitude.

Webster 1913