A manifestation of the Doppler effect in which an object appears bluer when it is moving towards the observer or the observer is moving towards it: The blue shift is a reduction in the wavelength of radiation given off by an oncoming celestial body.

Blue light has a higher frequency than other colors in the spectrum.

The blue shift is the opposite of the red shift.

Jurors selected for their special qualifications, like their higher educational level and intellectual skills; blue-ribbon panel: A blue-ribbon jury is considered by either side, prosecution or defense, to be ideal because of its perceived likelihood of rendering a verdict favorable to that side.