1) short for fucking awesome, thus used to express excitement or agreement
2) short for fucking a, thus used to express dissapointment or disagreement
1) You got Pixies tickets? Fucking A!
2) Fucking a I have a test tomarrow!
1) one who performs cunninglus
2) insult for a male slut
a nicer term than cuntmuncher
It doesn't matter if he doesn't pay, he's quite the nunu nibbler!