n r b 

No Reason Boner; an erection that pops up outta nowhere.
spoken as: en are bee, or nerb.

"Yeah man, the cop wanted me to get outta the car, but i had an N R B so i just took the heat."
"We broke up (other dude: "why man?"), got a fucking N R B at her grammas funeral."
"If i dont stop gettin nerbs i gonna cut the fucking thing off!!"

n r b by 6IXTY 1NE July 25, 2006

N.R.B. 

No reason Boner. A hard on achieved with no apparent explanation.

I got a N.R.B. this morning at church.
I got a N.R.B. right in the middle of Schindler's List.

N.R.B. by B.O.B. April 4, 2003

F.N.R.B. 

For No Reason Boner

Used often when one wants to discreetly express the fact that he is currently experiencing a boner for no apparent reason at all.

Dude 1: They just called your name... go get that diploma.

Dude 2: Shit. I don't know what to do. I've got a F.N.R.B.!

Dude 1: Ouch. Bad timing

F.N.R.B. by Worldwide Thugs September 14, 2006

n.r.b 

1.no reason boner
2.unexplainable boner

dude i got an n.r.b. in science.

n.r.b by joe mackdonald April 22, 2006

N.R.B 

N.R.B is an abbreviation for what is known as a "No Reason Boner".A No Reason Boner is when a male randomly "gets hard" for no apparent reason.Also see boner.

Man I have a wicked N.R.B right now.

N.R.B by rundmc March 2, 2006

N.R.B 

An Acronym for No Reason Boner

I had a major N.R.B in Geometry.

N.R.B by CJ McMastaKewlio February 9, 2009

N.R.B. 

Acronym for No Reason Boner. A random boner a guy gets for no apparent reason.

Zach; Did you see Evan got an N.R.B. in school today when he was akes to solve the problem on the board.

Ray; Yeah. How embarassing.

N.R.B. by John Dennis Riley February 6, 2008