foo 

Shape of mouth used in Irish Sign Language (ISL) by Deaf signers with following sign: fist ('F') at chin level shoots forward the fist sideways with index and long finger out in shape of gun barrell ('OO').

Used to describe someone who:
i) Tripped up big time - unintentionally;
ii) was easily lead on;
iii) believed a cock and bull story;
iv) holder of Darwin award

As signed:

'FOO' (laugh unbelievingly)
'YOU FOO' (look disgusted or sneery)
'HE FOO' (roll eyes at man admitting he was take in by some womans bullshit)
'SHE FOO' (look up and down fallen drunk woman in amazement)
'FOO?!' (Shake head in disbelief)

foo by ISL Slang Master February 6, 2004

foo 

that what must be fought. see foo fighters

Dave Grohl makes a living fighting foo.

foo by Seth Nicaragua February 6, 2004

foo 

Solitary ingredient of weight-watchers' Egg Foo Yung.

Use no egg, use no yung. Sprinkle with foo and serve.

foo by baldpuss January 26, 2005

foo 

short for "phooey"; term used when something goes unaccording to plan or when something unexpected happens.

"Foo! That wasn't supposed to happen!"

foo by kaili June 20, 2004

foo 

stuff fought by an awesome band called foo fighters

dude: man they are kicking the shit out of that foo
dude2: wtf is foo?
dude: your mom is foo, now shut up and listen

foo by foo fighter May 25, 2005

Foo 

The fleshy part of the human body that you sit on; Ideal for Bikers ;)

Look at the Foo on that..

Foo by PiOn December 29, 2004

Foo 

short for fool

shut up foo!!

Foo by deathjork January 20, 2009