|a. a radio wave with a wavelength in the range 10--100 metres|
|b. (as modifier): a short-wave broadcast|
|shortwave (shôrt'wāv') Pronunciation Key
A radio wave with a frequency between 5.9 megahertz and 26.1 megahertz. Shortwaves broadcast from the Earth's surface are reflected by the upper atmosphere and can travel great distances around the planet. The shortwave band of the electromagnetic spectrum is used for amateur radio communications.