- The definition of a stackup is when airplanes circle around at different heights while waiting to land.
An example of a stackup is what happens at an airport when a landing strip must be closed.
stackup definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
an arrangement of circling aircraft at various altitudes, each awaiting its turn to land
stackup definition by American Heritage Dictionary
A deployment of aircraft circling an airport at designated altitudes while awaiting instructions to land.