"What the fuck" is a vulgar slang phrase used to express astonishment, shock, incredulity, or disbelief. It is an intensive form of "what" and is often used to express extreme surprise or frustration. The phrase can also be used to express nonchalance or the dismissal of any consequences of something one is about to do. The word "fuck" itself is a vulgar term that can be used as a verb to mean "to engage in coitus with" or as a noun to mean "an act of copulation" or "a sexual partner".