redshift

or red shift

[ red-shift ]
/ ˈrɛdˌʃɪft /

noun Astronomy.

a shift toward longer wavelengths of the spectral lines emitted by a celestial object that is caused by the object moving away from the earth.

Origin of redshift

First recorded in 1920–25; red1 + shift

British Dictionary definitions for redshift

redshift
/ (ˈredˌʃɪft) /

noun

a shift in the lines of the spectrum of an astronomical object towards a longer wavelength (the red end of an optical spectrum), relative to the wavelength of these lines in the terrestrial spectrum, usually as a result of the Doppler effect caused by the recession of the object Compare: blueshift