- the complete range of electromagnetic radiation from the longest radio waves (wavelength 105 metres) to the shortest gamma radiation (wavelength 10–13 metre)
WordReference Random House Unabridged Dictionary of American English © 2026
elec′tromagnet′ic spec′trum,
- Electricitythe entire spectrum, considered as a continuum, of all kinds of electric, magnetic, and visible radiation, from gamma rays having a wavelength of 0.001 angstrom to long waves having a wavelength of more than 1 million km.
- 1935–40
Collins Concise English Dictionary © HarperCollins Publishers::
electromagnetic spectrum n
'electromagnetic spectrum' also found in these entries (note: many are not synonyms or translations):