An exclamation of unhappiness. Often used when supremely pissed off. While fucking a is generally a good thing (meaning fucking amazing), this is a bad thing.

An exclamation of which its origins lead to a middle school in Seattle, WA. On a school camping trip, they kids swore so much that the teacher, (Tom) trold them they could only say one swear word. They chose "Fucking A' Tom was later addded.