'Diffraction' definitions:

Definition of 'diffraction'

(from WordNet)
noun
When light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands

Definition of 'Diffraction'

From: GCIDE
  • Diffraction \Dif*frac"tion\, n. [Cf. F. diffraction.] (Opt.) The deflection and decomposition of light in passing by the edges of opaque bodies or through narrow slits, causing the appearance of parallel bands or fringes of prismatic colors, as by the action of a grating of fine lines or bars. [1913 Webster]
  • Remarked by Grimaldi (1665), and referred by him to a property of light which he called diffraction. --Whewell. [1913 Webster]
  • Diffraction grating. (Optics) See under Grating.
  • Diffraction spectrum. (Optics) See under Spectrum. [1913 Webster]