Verb
(slang, intransitive) To give up or cravenly abandon something difficult.
When the going got tough, he punked out.
(slang, transitive, almost always used in the passive voice) To treat as a punk (either as a worthless person or the bottom in a male-male relationship, especially a nonconsenting prison relationship).
He knew if he didn't stand up for himself, he'd be punked out by someone stronger.
I think that what's perceived as punk out in shopping malls or in chain stores or on MTV has almost nothing to do with what punk is about. Jello Biafra
If something is visceral and unsettling for me, my job is to not look away, not to punk out. Sometimes the dark things come from places inside me, experiences I've had, that need to be transformed. Lilith Saintcrow