Procure por qualquer palavra, como doxx:
 
1.
The true usage of the phrase is to claim that you simply 'do not know', however, the phrase is often interpreted as 'Fuck Nose' which may cause offence to the listner. This mis-interpretation is often replied to using 'Cunt Face' which is regarded as the appropriate answer.
"What time is Adam supposed be be here?
"Fuck Knows"
"Only asking...Cunt Face"
por Mystick Havok 21 de Janeiro de 2008
 
2.
An abbreviation or slang used to by many for a way to say "I don't know"
Boy1: Dude, what's the time?
Boy2: Fuck knows
por Dalmas 02 de Janeiro de 2014