Plain English Meaning
The strip of pavement or prepared surface where aircraft land and take off. Each runway has a number based on the compass direction it points.
Full Definition
A defined rectangular area on a land airport prepared for the landing and takeoff of aircraft. Runways are identified by a number representing the magnetic heading of their centerline rounded to the nearest ten degrees, with the trailing zero dropped (for example, runway 27 points roughly 270° magnetic).
Context Anchor
You see and use this term in airport signs, airport diagrams, taxi instructions, landing clearances, takeoff clearances, and preflight planning.