A semi-meme, cousin of lolwut. It's something you say when you are either:
Disturbed, confused, angry, scared, ect.
It's like saying "wtf" only more bad ass.
Person 1: Wanna see my dick?
Person 2: Da fuq bro, no!
It's like saying WTF but in a much awesomer way, you say it when you are completly confused to what a specific person or object is doing.
Guy1: *sees a cat doing a handstand
GUY1: DA FUQ?