The response when one of your friends offers you a fist pound and you shake his fist leaving him perplexed.
After Utley's grand slam, Ryan Howard, Pat Burrell and Jimmy Rollins gave him a fist pound but Jamie Moyer threw him a changeup.
by headdoc July 25, 2008
1 more definition
alter method of operation
The cops are on to us, we'd better change up.
by Jim King December 18, 2004