f00! 

1347 5p34k version of "Fool"
one who is foolish or has foolish tendancies.

i'll kick yo ass f00!

f00! by Crackity Jones June 30, 2002

f00 

13375p34k(leetspeak) for 'fool' 'chump' or 'one who has been roxored' used in Online gaming and by leetspeakers everywhere.

I just g4nk3d that f00!

f00 by Jabuwa-ku December 13, 2003

f00 

l337 for fool

I pity da f00 who doesn't dial collect

f00 by MonJoe May 15, 2003

f00 

In programming, F00 is what you call a variable with a vague name in which you store a color.
#F00 is the color code for bright red in simplified rgb hex. Foo is a variable name chosen by lazy programmers who can't come up with better variable names.
Plural: f00s
Verb: f00ing

Person 1: I just made this javascript code:

var meh = "#FFF";
var iCantThinkOfWhatToNameThis = "#BADA55";
var F00 = "#F00";
var bar = "#123456";
Person 2: Stop f00ing your code up with so many f00s.

f00 by Potatoes! June 13, 2014

f00 

Derived from computer music (tracker) code. The "f" represents speed and "00" means that the song (actually pattern) stops.
So basically there's also my redefinintion for the rock band Foo Fighters... I don't think they're "fighting the fools", but rather "fighting to keep the music playing" or something in that direction ;)

bahrg i dont have one,just let me post this shit

f00 by jallah February 11, 2005

f00 

fool

f00 by lol October 8, 2003

f00 

A fool, sucker or chump.

Man, did you peep that f00 trying to gank my wallet?

f00 by Sloppy White February 14, 2003