Plain English Meaning
A normal ILS approach flown into airports where two parallel runways are close together. Special radar watches the planes on both runways closely, so two aircraft can land at the same time on different runways safely. Pilots must listen on two radios and be ready to turn away quickly if told.
Full Definition
An instrument approach that uses a standard Instrument Landing System for vertical and lateral guidance to the runway, while air traffic control monitors the aircraft's position with high-update-rate radar (Precision Runway Monitor) to allow simultaneous independent approaches to closely spaced parallel runways. The approach is conducted under that include two and being prepared to execute an immediate if another aircraft deviates toward the .