Pronunciation: (di-frak'shun), [key]
1. the phenomenon exhibited by wave fronts that, passing the edge of an opaque body, are modulated, thereby causing a redistribution of energy within the front: it is detectable in light waves by the presence of a pattern of closely spaced dark and light bands (diffrac'tion pat"tern) at the edge of a shadow.
2. the bending of waves, esp. sound and light waves, around obstacles in their path.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.