Plain English Meaning
A radio signal that hugs the ground as it travels, bending with the Earth's curve instead of going straight out into space.
Full Definition
A radio wave that travels along the surface of the Earth, following its curvature, rather than radiating into the sky. Ground waves are most effective at low and medium frequencies and are used by navigation aids such as the NDB (Non-Directional Beacon).
Context Anchor
Seen in instrument flying and radio navigation discussions, especially when learning how some navigation beacons send signals to aircraft.
Derivation
Plain English: 'ground' meaning the Earth's surface, and 'wave' meaning a radio wave. The name describes how the signal travels — along the ground rather than through the upper .