- Electricity. a radio wave shorter than that used in AM broadcasting, corresponding to frequencies of over 1600 kilohertz: used for long-distance reception or transmission.
- shortwave radio.
- Physics. a wave of electromagnetic radiation equal in length to, or shorter than, the wavelength of visible light.
- of, relating to, or using shortwaves.
verb (used with or without object), short·waved, short·wav·ing.
- to transmit by shortwaves.
- 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.