n. (also Doppler shift) Physics an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move towards (or away) from each other.
[ C. J. Doppler, Austrian physicist d. 1853 ]
DOPPLER EFFECT
Meaning of DOPPLER EFFECT in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012