Meaning of angular dispersion

an'gular disper'sion

Pronunciation: [key]
— Optics. Optics.
  1. a measure of the angular separation of light rays of different wavelength or color traversing a prism or diffraction grating, equal to the rate of change of the angle of deviation with respect to the change in wavelength.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.