1 definition by Istvan Sengir
(Face Book Best Friend). (n) a person that you do not know at all, but for some reason feel the need to respond to any number of your posts as a close friend.
Sally: No feeling 100% percent today.
FBBF: I am so sorry to hear that.
Sally: Thanks, to my newest FBBF.
FBBF: I am so sorry to hear that.
Sally: Thanks, to my newest FBBF.
by Istvan Sengir May 14, 2010