Dif-frăc'tion, n.

(-frăk'shun), n. [Fr. diffraction, It. diffrazione. See supra.] (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.

Remarked by Grimaldi (1665), and referred by him to a property of light which he called diffraction. Whewell.