n. & v.
--n. (pl. -os)
1. (often attrib.) a the transmission and reception of sound messages etc. by electromagnetic waves of radio-frequency (cf. WIRELESS). b an apparatus for receiving, broadcasting, or transmitting radio signals. c a message sent or received by radio.
2 a sound broadcasting in general (prefers the radio). b a broadcasting station or channel (Radio One).
--v. (-oes, -oed)
1. tr. a send (a message) by radio. b send a message to (a person) by radio.
2 intr. communicate or broadcast by radio.
Phrases and idioms:
radio astronomy the branch of astronomy concerned with the radio-frequency range of the electromagnetic spectrum. radio cab (or car) a cab or car equipped with a two-way radio. radio fix the position of an aircraft, ship, etc., found by radio. radio galaxy a galaxy emitting radiation in the radio-frequency range of the electromagnetic spectrum. radio ham see HAM. radio star a small star etc. emitting strong radio waves. radio telescope a directional aerial system for collecting and analysing radiation in the radio-frequency range from stars etc.
Etymology: short for radio-telegraphy etc.