barrel roll 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.
a complete roll made by an airplane around its longitudinal axis while it simultaneously completes one spiral revolution in the air, as a chamber of a revolver turning in relationship to its gun barrel
barrel roll definition by American Heritage Dictionary
A flight maneuver in which an airplane makes a complete rotation on its longitudinal axis while approximately maintaining its original direction.