One who believes he is awesome beyond belief but who is in reality the worlds fattest(not really phatest)loser. Phat Matt usually gives himself the name to appear cool instead of just fat.
Who is that driving that piece of shit car? Ohh it's Phat Matt
by FBhater November 11, 2006
One who is awesome beyond belief.
Look at him, he is so phat matt!
by Un-Known August 21, 2006