A man using a jackhammer.
jackhammer 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 portable type of pneumatic hammer, used for breaking up concrete, rock, etc.
Origin: jack- plush hammer
jackhammer definition by American Heritage Dictionary
A hand-held machine for drilling rock and breaking up pavement, operated by compressed air.
- jackˈhamˌmer verb