radiotelegraph n telegraphy that uses transmission by radio rather than by wire n the use of radio to send telegraphic messages (usually by Morse code) Usage(s) Today, Transradio news goes by teletype and radiotelegraph to 288 radio stations. Argentina is the only one of the 21 American republics now permitting radiotelephone and radiotelegraph communications with Japan, Germany and Italy. Synonym(s) radiotelegraphy wireless telegraphy wireless telegraph