Definition of masers:
(n) :
(physics) a device for the coherent amplification or generation of electromagnetic radiation (especially of microwave frequency) by the use of excitation energy in resonant atomic or molecular systems
(n) :
(astronomy) Any celestial object that generates microwaves using the same method
(n) :
Obsolete spelling of mazer. [(obsolete) The maple tree, or maple wood.]
(n) :
Acronym of microwave amplification by the stimulated emission of radiation.