Short for freeze the fuck up. You say this when you're pissed off that something you put in the freezer isn't freezing fast enough.
Joe: I really wish this beer would hurry and ftfu..
Fucked the fuck up.
In reference to extreme levels of inebriation from alcohol, weed, or other drugs. Usually posted as a facebook status, sent as a text message, or exclaimed as 'FUCKED THE FUCK UP'
The origin of the term seems to be as a variation of the popular STFU.
FB: Nat G is FTFUUU
Text: im soo ftfu sadf
Exclaimed: THIS SHOTS FOR YOU! I'M FUCKED THE FUCK UP!