Non-Directional Beacon. A medium-frequency navigational aid which transmits non-directional signals, superimposed with a Morse code identifier and received by an aircraft Found on http://airodyssey.net/reference/glossary/
Non-Directional Beacon. An LF, MF, or UHF radio beacon transmitting non-directional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine his bearing to or from the radio beacon and "home" on or track to or from the station. When the radio beacon is installed in conjuncion with the Instrument Landing Syste... Found on http://www.aerofiles.com/glossary.html
Non-Directional radio Beacon. A low-power AM radio transmitter on the ground used as a navigational aid. See also ADF Found on https://www.encyclo.co.uk/local/22326