1) when all of the sudden you are hard...

2) when you hear good news and you get a boner!

3) when a black man touches you

4) when a jew finds a penny

5) pretty much any time you listen to Creed, Nickelback, or Naked Truth

6) when you remember something from a long time ago (see nostalgia boner)
#1
Fuckhead: DUDE DID YOU HEAR THE NEW NICKELBACK CD?!?!?!!?!?

Even More Fuckhead: YEAH! I GOT A RANDOM BONER!!!!

#2
Naked Truth Fan: I THINK! I GET! YOUR POINT!

Other guy: WOAH RANDOM BONER!

#3
Black Guy: *touches some guys dick*
Some guy: RANDOM BONER!
by @xtylerryanx January 8, 2012
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<Also known as R.B.S.>

An affliction that oppresses young teenagers. Often considered a disease, Random Boner Syndrom is most active in those teenagers who are socially awkward, causing even more distress, embarrassment, and nervousness. Happening in random intervals, R.B.S. causes blood to flow at an accelerated pace into a young male's genitalia. This happening is known to created stiffness in one's genitalia; stiffness almost perceived as that of a bone. Even when not aroused, this will occur as a result of R.B.S.
There is one time when R.B.S. is much more likely to result. This occasion is when talking, conversing, or being in the vicinity to attractive girls or women.
"I was so mortified when I was talking to Clementine and my Random Boner Syndrome acted up again."

"As we danced in the sunset, she noticed my donk slowly rise to her hip. I said, 'I have R.B.S. I swear to God!' She doesn't talk to me anymore."

"Some say R.B.S. is a curse... I see it as a gift..." said the creepy mall-rat as he ate Dippin' Dots in the shadows.

by Booty McShakespeare March 9, 2009
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Sometimes referred to as RBS, Random Boner Syndrome is a severe medical condition plaguing men around the world. As implied, a young male will, unexpectedly get and erection boner often at an inappropriate time. It is completely random, with no visual or mental stimulation required to cause it. Most males will not experience this very often after puberty.
Guy1: Dude, do you got a hotdog in your pants, or are you just happy to see me?

Guy2: OH NO, Random Boner Syndrome (RBS) strikes again!
by Ymerej Kcirrag July 18, 2008
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A boner that happens randomly and unexpectedly. Usually it is not a good thing. They generally tend to happen at the worst possible time or a time when it is not acceptable or called for. Sometimes it happens when a man is not even turned on or horney.
Man, it was weird. I was just sitting in math class and boom, random occuring boner. It made no sense, there wasn't even a hot girl in the room
by Tojo Hiroshita November 24, 2010
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