Plain English Meaning
A radio station on the ground that lets a pilot work out which direction they are from it, or which direction to fly to reach it, by tuning in and reading the bearing on a cockpit instrument.
Full Definition
A ground-based radio navigation aid that transmits signals in the VHF band (108.0–117.95 MHz), allowing a suitably equipped aircraft to determine its bearing to or from the station along any of 360 selectable courses, called radials, measured in degrees from magnetic north.
Context Anchor
Seen on aviation , in , and during instrument when choosing or following based on ground radio stations.