Short for boner for no reason.
Man I was watching wrestling when I got hit with a BFNR!
by Jason August 22, 2004
Bitch For No Reason
That drunk girl Jade was such a BFNR last night.
by vinhsanity January 11, 2009
BFNR is a code word used in high schools. BFRN = Boner for no reason, is when you get a boner (for no specific cause). There is also BFA = Boner for ass, and is exactly what it says.
Dude, she is so hot. I have a BFNR!!
by xSeBaZz January 16, 2016