Radio-telegraph is a term that refers to the transmission of communication using radio waves. It is also commonly known as wireless telegraphy or simply, radio. Some of the synonyms for radio-telegraph that can be used include wireless communication, radio communication, and telegraphy. These synonyms are often used interchangeably to refer to the transmission of communication using radio waves. Other related terms include radio transmission, wireless transmission, and radio waves. Radio-telegraphy has been used for communication purposes for over a century and continues to be an important technology in modern times.