The apparent angular elevation of the heavenly bodies above their true places, caused by the refraction of the rays of light in their passage through the Earth's atmosphere.

Synonym of atmospheric refraction

plural of refracting telescope

A telescope which produces a magnified image by refracting light through a series of lenses housed in a tube, with a light-gathering objective lens at one end and an eyepiece at the other.

(physics) The ratio of the speed of light in air or vacuum to that in another medium.

plural of refractive index

plural of refractive power

Synonym of optical power

Third-person singular simple present indicative form of refractionate

To fractionate again or further