maser

from WordNet (r) 3.0 (2006)

maser
    n 1: 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

from The Collaborative International Dictionary of English v.0.48

maser \ma"ser\, n.
   1. Same as {Mazer}.
      [1913 Webster]

   2. (Physics) [from Microwave Amplification by Stimulated
      Emission of Radiation.] An electronic device producing
      coherent monochromatic microwave radiation; it produces
      less noise than other forms of microwave oscillator.
      [acronym]
      [PJC] MASH