Plain English Meaning
Flying straight toward a ground radio beacon, adjusting your heading so the wind doesn't push you off the line you want to fly.
Full Definition
Flying a desired course directly toward an NDB (non-directional beacon) using the ADF (automatic direction finder), correcting for wind by establishing a heading that keeps the aircraft on the selected bearing to the station. The pilot adjusts heading so the relative bearing on the ADF indicator compensates for any drift, keeping the actual ground track aligned with the inbound course.
Context Anchor
Seen when using the ADF, the automatic direction finder, to toward a ground radio beacon during .