Plain English Meaning
It is the rectangular path pilots fly around an airport when arriving or departing, with set legs that everyone follows so all aircraft move in the same predictable order.
Full Definition
A standardized rectangular flight path flown by aircraft around an airport when taking off or landing, consisting of five named legs: departure, crosswind, downwind, base, and final. The pattern provides a predictable flow of traffic so pilots can sequence safely with other aircraft, and it is normally flown to the left of the runway unless right traffic is published.
Context Anchor
You encounter this term when learning takeoffs and landings, approaching an airport, departing an airport, or practicing near a runway.