Longman Dictionary of Contemporary English
short wave
noun
EXAMPLES FROM CORPUS
▪ Broadcasting was on short wave only and at such low power that the reception area was limited, scattered and unpredictable.
▪ It says that, in affected areas, only a minority listens on short wave.
Wiktionary
short wave
n. (alternative spelling of shortwave English)
WordNet
short wave
n. a radio wave with a wavelength less than 100 meters (a frequency greater than 3 megaHertz)
Usage examples of "short wave".
On the Moon, powerful radio stations were capable of hurling ultra-short wave messages across the quarter million miles to Earth.