The act of "derping" or "D.E.R.P-ing" can either be physical or verbal in nature and is always done intentionally... or maybe not if you're lucky.
1. Peter, Samir and I took the company car to lunch yesterday and in the act of derping we almost had all four wheels of the car off the ground. It was awesome!!!
2. You hate your job so much that you keep breaking the copy machine intenionally, but of course nobody knows this. ...Unfortunately, this will often lead you to overhear the statement "I hate this printer it never freaking works."
3. Someone hates their job at the Hamburger Hut so much that they like to tell people Hamburger Hut undercooks the beef patties just so people won't eat there.
Player 2: Aaaahgh...
Player 1: DERP!