Maser (noun)

1. A device that amplifies electromagnetic waves, especially microwaves, by the process of stimulated emission.
2. A device that generates coherent microwave radiation using the principle of stimulated emission.

Origin:

Acronym of microwave amplification by stimulated emission of radiation.

Examples:

1. Maser is an acronym for Microwave Amplification by Stimulated Emission of Radiation.
2. The maser is a predecessor of the laser.
3. The maser was first demonstrated in the 1950s.
4. The maser was used to amplify microwave signals.
5. The maser was used in the early days of radio astronomy.