Plain English Meaning

Flashing yellow lights placed where a taxiway meets a runway. They flash to remind you that a runway is just ahead, so you stop and check before going any further.

Full Definition

A pair of alternately flashing yellow lights installed at taxiway/runway intersections to warn pilots and vehicle drivers that they are about to enter or cross an active runway. They may be installed either elevated on each side of the taxiway (elevated runway guard lights) or in-pavement across the taxiway centerline (in-pavement runway guard lights), and they serve as a clear visual cue that a hold-short point is ahead.

Context Anchor

Seen while taxiing near a runway, especially at taxiway/runway intersections and in low-visibility airport movement systems.

Derivation

The name describes the function directly: lights that 'guard' the runway by alerting anyone approaching it. No deeper origin needed.