1) A form of wireless communications in which the output of the transmitter takes the form of dissipating electromagnetic radiation which spreads outward from the antenna through free space. The signal strength drops off as the square of the distance from the source of radiation. Distant radio receivers have to be very sensitive to detect signals that can measure only a few microvolts per meter in strength.
2) A communications device allowing the wireless transmission through space of audible signals encoded in electromagnetic waves in the approximate frequency range from 10 kilohertz to 300,000 megahertz.
3) (maratime definition) An instrument that uses electromagnetic waves to communicate with other vessels. VHF
radios are common for marine use, but are limited in range. HF
-SSB (single sideband) radios have longer ranges.
4) an electronic receiver that detects and demodulates and amplifies transmitted signals
5) Radio is a system for the distribution of advertisement, chiefly brand advertisement for package-goods, and advertisement for recorded music sold by BigCos. To describe radio as a system for the diffusion of news, or of music, or as a technology, would be not only inaccurate but actually misleading. Radio is a creature of the advertising business, as its child, TV. television
6) Transmit messages via radio waves, usally on a set wavelength, or frequency.