Plain English Meaning
A test signal broadcast through the air from a special ground station so a pilot can check whether the aircraft's VOR navigation receiver is reading correctly.
Full Definition
A VOR test signal transmitted over the air from a designated ground facility, used by pilots to verify the accuracy of an aircraft's VOR receiver. At certain airports, an FAA-designated VOR Test Facility (VOT) broadcasts a signal that, when properly tuned and received, should produce a specific known indication on the VOR display, allowing the pilot to confirm the receiver is within .