"wireless transmission with radio waves," 1907, abstracted from earlier combinations such as radiophone
(1881) and radio-telegraphy
(1898), from radio-,
comb. form of radiation
(q.v.). Use for "radio receiver" is first attested 1917; sense of "sound broadcasting as a medium" is from 1922. Wireless
remained more widespread until World War II, when military preference for radio
turned the tables. The verb is attested from 1919.