A question asked in disbelief with an extremely sarcastic tone questioning someones actions or statement. It is a way to point out someones stupidity in the form of a question.
The verbal tic of dunderheads, morons and wannabe Californians (read: Seattle denizens and their ilk.) It is not intended as an actual question but rather is the reactionary knee-jerk of someone who does not think before opening the mouth.
Me: I just got this latte for uber cheap at the Starbucks on the corner.
Idiot I'm talking to: Are you serious?
Me: No, I'm just pulling your motherfucking leg. Of COURSE I'm serious!
An expression uttered subsequent to an unforeseen response; used in a joking sense; can carry a sarcastic tone; usually accompanied by a dramatic step back from the person; although it carries a question mark it doesn't require an answer.
Paul: "How'd ye get on in the match today?"
Shane: "We lost by 4 goals..."
Paul: "Are you serious!?"
Easter egg in CoD MW. In the mission "clean house" you can find a baby. If you somehow shoot or uhhh harm the baby, the screen will go black with the words saying "children are non combatants" do this 3 times and the screen will now say "are you serious" and kicks you out of the mission
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).