An expression used in frustration. The equivalent of "Arg," popularly used by teens or young kids trying to act like teens.
Friend 1: Hey, can you open this jar for me?
Friend 2: Sure thing! (takes jar and struggles)
Friend 2: BARG!!! I can't open this crap!
Friend 3: Here, let me. (pops lid off with ease)
Friend 2: .... BARG!!!