To become angry. I didn't tell Dad that I scratched up his car because I knew he'd get mad. You lied to me, so of course I got mad!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
get mad (at something)
to muster all one's physical and mental resources in order to do something difficult. Come on, Bill. If you're going to lift your end of the piano, you're going to have to get mad at it. The sergeant keeps yelling, "Work, work! Push, push! Come on, you guys, get mad!"
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.