radioteletype
(ˌreɪdɪəʊˈtɛlɪˌtaɪp) n1. (Telecommunications) a teleprinter that transmits or receives information by means of radio waves rather than by cable or wire
2. (Telecommunications) a network of such devices widely used for communicating news, messages, information, etc
Abbreviations: RTT or RTTYCollins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014