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1.
A young kid or someone that could still be considered a punk ass kid who is rude, disrespectful or just generally unpleasant. Often abbreviated as being a "PJ". Those who earn the title as a punk jerk are often times angered by the phrase and will protest its usage. Due to the nature of the term it is considered safe enough to use in a public setting without sounding overly harsh but still being able to convey the message of annoyance towards one's attitude or demeanor. People who answer sarcastically when asked questions or never give you a straight answer are punk jerks.

Can also be used to describe someone who can be considered mature but often acts like someone who is much younger.
Friend 1: Did you drive my car last and not put any gas in it?
Friend 2: Idk
Friend 1: Why didn't you refill the tank?
Friend 2: Not my car, not my responsibility.
Friend 1: Don't be a punk jerk
Friend 2: DON'T CALL ME A PJ!

or

Friend 1: Play it cool around that girl, I want to ask her out.
Friend 2: Ayo bitch dis nig wants you
Friend 1: Stop being such a PJ, you're like 40
Friend 2: My parents never really loved me that's all.
Friend 1: Stop with the bullshit sarcasm and act your age punk jerk.
by Fatty McSwagfag January 11, 2014