Same defination as fuck but it is stated with not such certainity and confidence. It is stated very smoothly and calmly, and stated as a question. Usually stated when one is not sure if he/she should actually say fuck, or doesn't find it necessary to say fuck with aggression.
The annoying moment when your on the computer on facebook and suddenly a fly appears and starts annoying you a lot! And then you feel the urge to go to the toilet but you dont want to move of your place because your scared someones going to talk to you on facebook but soon you realize no ones going to talk to you so you go to the toilet. When you come back 20,000 people have talked to youm and you go FUCK!