slang To abandon, give up, or refuse to do something out of cowardice. Tom was supposed to keep a look out while I robbed the liquor store, but he punked out at the last minute. He talked a big talk, but he punked out the moment I stood up to fight him.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
Sl. to chicken out (of something); to withdraw from something in cowardice. He was supposed to ask her out, but he punked out at the last minute. Come on! Stick with it! Don't punk out!
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
1. in. to chicken out. He was supposed to ask her out, but he punked out at the last minute.
2. in. to become a punker. If my kids ever punked out and looked like that, I think I’d clobber them.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.