Arguarf
An exclamation of shock, surprise or annoyance. Essentially, it is used similarly to the phrase "oh my god."
Person1: Arguarf! This corndog tastes like a unicorn farted on it!
Person2: Is that a good thing or a bad thing?
Person1: It's a good thing you fucking dumbass.
Person2: Is that a good thing or a bad thing?
Person1: It's a good thing you fucking dumbass.