Radio is a word which is an American citizen by birth.
There may not be many people now living who are older than when the term radio was born. When the Italian physicist Marconi, the Italian electrical engineer known as the "Father of Radio" (1874-1937), showed the world the way to wireless communications, inventors and interested students every where started to put up sending stations.
No license was required because everyone could do as he pleased in this newly developed field and as a result, many new expressions came into use; such as, radiotelegraph, radiotelegraphy, radiotelegram, and radiotelephony.
Although the term wireless had at first been widely used in the U.S., as it still is in England, it was not very long before these longer expression led to the adoption in the United States of the much shorter term radio for all kinds of wireless communications.
In fact, several other countries have also adopted radio into their languages and even England has made some gains on the older term wireless and are at least aware of the applications of the term radio.
Etymology: "wireless transmission of voice signals with radio waves" (1907), abstracted from earlier combinations such as radio-receiver (1903), radiophone (1881), radio-telegraphy (1898); from radio-, as a form of Latin radius, "beam".
Use for "radio receiver" was first indicated in 1913; while the sense of "sound broadcasting as a medium" is also from 1913.