REFRACTION

n. bending of light or energy as it passes from one medium into a second medium in which the energy travels at a different speed

Refraction is the change in direction of a wave due to a change in its speed. This is most commonly seen when a wave passes from one medium to another. Refraction of light is the most commonly seen example, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another or when water waves move into water of a different depth.
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Refraction /re·frac·tion/ 1. the act or process of refracting; specifically, the determination of the refractive errors of the eye and their [more]Refraction - Community and Resources

Noun
1. the change in direction of a propagating wave (light or sound) when passing from one medium to another
(hypernym) physical phenomenon
(hyponym) double refraction, birefringence
(derivation) refract
2. the amount by which a propagating wave is bent
(synonym) deflection, deflexion
(hypernym) bending, bend

n. refraction, bending of light or energy as it passes from one medium into a second medium in which the energy travels at a different speed