dif|frac|tion «dih FRAK shuhn», noun. Physics.
1. a spreading of light around an obstacle into a series of light and dark bands or into colored bands of the spectrum: »
Newton had attempted to infer from…diffraction phenomena the size of the corpuscles of matter (Scientific American).
2. a similar spreading of other waves, such as sound waves, as when a wave front changes from a straight line to a curved line.
3. a change in the direction of an electron beam, such as occurs when the beam comes in contact with a crystal of nickel.
Useful english dictionary. 2012.