radial engine 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 internal combustion engine with cylinders arranged radially like wheel spokes
radial engine definition by American Heritage Dictionary
An internal-combustion engine, formerly used in propeller-driven aircraft, with cylinders arranged radially around the crankshaft.