diffraction
Americannoun
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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 diffraction pattern at the edge of a shadow.
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the bending of waves, especially sound and light waves, around obstacles in their path.
noun
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physics a deviation in the direction of a wave at the edge of an obstacle in its path
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any phenomenon caused by diffraction and interference of light, such as the formation of light and dark fringes by the passage of light through a small aperture
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deflection of sound waves caused by an obstacle or by nonhomogeneity of a medium
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The bending and spreading of a wave, such as a light wave, around the edge of an object.
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See more at wave
Etymology
Origin of diffraction
1665–75; < New Latin diffrāctiōn- (stem of diffrāctiō ) a breaking up, equivalent to Latin diffrāct ( us ) broken up (past participle of diffringere ) + -iōn- -ion. See dif-, fraction
Explanation
Diffraction is the process of light bending around an obstacle or spreading out after it moves through a small space. If you study physics, you'll learn about the diffraction of light waves. Any kind of wave can experience diffraction, including sound, radio, and water. It's most common to hear about the diffraction of light, which can be seen in the reflection of an image through a pinhole camera or the bright ring of light around the sun or the moon. The root of diffraction is the Latin word diffringere, "break into pieces," from dis, "apart," and frangere, "to break."
Vocabulary lists containing diffraction
Give Me a Break!: Fract and Frag
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Waves and Wave Properties - Introductory
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Waves and Wave Properties - Middle School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
This effectively compressed the light into a region much smaller than its wavelength, allowing it to bypass the diffraction limit and reveal much finer details.
From Science Daily • Mar. 17, 2026
Instead of focusing light through glass, the system uses an array of coded sensors placed at different locations within a diffraction plane.
From Science Daily • Jan. 10, 2026
Watson became fascinated by the new technique of diffraction whereby X-rays were bounced off atoms to reveal their inner structures.
From BBC • Nov. 7, 2025
There, he became interested in the new technique of diffraction, in which X-rays were bounced off atoms to reveal their inner structures.
From BBC • Nov. 7, 2025
The next scientific step was to compare seriously the experimental X-ray data with the diffraction pattern predicted by our model.
From "Double Helix" by James D. Watson
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.