A radio wave having a wavelength between 1 and 10 mm (corresponding to a frequency between 30 and 300 GHz); chiefly attributive, designating equipment or techniques which use or measure these waves.
Origin
1950s; earliest use found in Science News.
Definition of millimetre wave in US English:
millimetre wave
(USmillimeter wave)
noun
Astronomy Physics
A radio wave having a wavelength between 1 and 10 mm (corresponding to a frequency between 30 and 300 GHz); chiefly attributive, designating equipment or techniques which use or measure these waves.