compression ratio 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.
in an internal-combustion engine, the ratio of the largest volume to the smallest volume of a cylinder, measured before and after the compressing action of the piston
compression ratio definition by American Heritage Dictionary
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
In an internal combustion engine, the ratio of the volume between the piston and cylinder head before and after a compression stroke.