a chute down which logs can slide
"The logger carefully pushed the heavy timber onto the snowy runway so it could slide straight to the river."
a narrow platform extending from the stage into the audience in a theater or nightclub etc.
"The actress walked down the runway to greet the cheering crowd at the end of the show."
a strip of level paved surface where planes can take off and land
"The pilot lined up on the runway to prepare for takeoff as the fog began to lift."
A defined, narrow section of land or an artificial structure used for access.
"The private airstrip served as a runway for our small aircraft to safely land in the remote valley."
In plain English: A runway is a long, flat strip of ground where airplanes take off and land.
"The model walked down the runway wearing her new dress."
Usage: A runway refers specifically to the paved strip at an airport where aircraft take off and land, distinct from grassy fields or taxiways. Do not confuse this with a fashion show platform, which is also called a runway but serves a completely different purpose in everyday conversation.
The word runway is a straightforward combination of run and way. It was first used to describe the strip on an airfield where aircraft take off and land because that is exactly what planes do there.