A runway is a long, flat strip of pavement where airplanes take off and land. Runways need to be extremely smooth and strong because planes travel at high speeds and weigh hundreds of thousands of pounds. At major airports, runways can stretch for two miles or more to give heavy jets enough space to build up speed for takeoff or slow down safely after landing. Smaller airports serving private planes might have much shorter runways.

The word also describes the narrow elevated platform where fashion models walk during clothing shows. Designers present their new collections by having models stride down the runway (also called a catwalk) while audiences watch from both sides. The fashion runway gets its name from the airport runway: both are long, straight paths designed for smooth, confident movement.

When someone has a clear runway, they have an unobstructed path forward to accomplish something. A student with summer vacation ahead might say they have a clear runway to finally read all the books on their list, meaning nothing stands in their way.