maser

n.	1.	Same as Mazer.
	2.	(Physics) An electronic device producing coherent monochromatic microwave radiation; it produces less noise than other forms of microwave oscillator.

Noun

1.

maser - an acronym for microwave amplification by stimulated emission of radiation; an amplifier that works on the same principle as a laser and emits coherent microwave radiation

amplifier, gas maser