FU can act as an adjective describing units in RTS games. It stands for Fully Upgraded. Mostly seen in forums, rather than in games.
a vietnamese noodle dish, that is bomb as hell, and you eat it with greens, bean sprouts, and hot green peppers.
fu by ChrisissoooooooooCool October 12, 2004
fu by Da Shizzle December 23, 2003
fu by Ladey Casey September 12, 2004
"Look at that. Its the FU!"
fu by Ben Parker January 13, 2008