An exclamation, akin to "Oh, gosh!" or "Oh my God", used to express frustration, disbelief, or unbelievable tiredness. Can also be said in reaction to someone jumping out of your closet and scaring the shit out of you.
More often used by chicks than guys, but your mileage may vary. Best when pronounced with a Wisconson accent.
Saz: Suck it up, you wuss.