rainboner 

A gay man's erection.

Elton John had a rather apparent rainboner during his last performance.

rainboner by pinkpanties24 November 2, 2011

brain boner 

Something that strikes a chord in someone's thinking, creating a spur of "enlightenment" and stimulation in knowledge, especially in subjects like philosophy & logic.

John: Hey, have you seen that recent philosophical discussion between XXX and YYY on YouTube?

Peter: Yeah, it was so good it gave me a brain boner.

brain boner by nullswitch March 6, 2011

Brain boner 

The feeling you get when you are having a lively discussion or listening to an engaging lecture and everything makes sense and it gives you a bunch of new ideas about the topic at hand. The intellectual equivalent of an erection.

DeSean: oh man, that lecture given by Dr. Kobilka about G protein-coupled receptor dynamics gave me a massive brain boner.

Derrick: uhh...right, yeah, totally dude. *pssst* Jimmy, I think we need to re-evaluate our friendship with DeSean...

Jimmy: agreed.

Brain boner by Longrod Von Hugedong May 26, 2016

Brain Boner 

When you are so intellectually stimulated your brain gets a boner.

You: Did you guys check out my new 3D TV?

Me: Yeah, major brain boner.

Used when describing something that intellectually "turned" you on.

Brain Boner by The Comet March 26, 2011

Brain Boner 

When you are talking and then have a random smart moment.

"Your mom just had a brain boner about robotics"

Brain Boner by Expression of happiness July 22, 2014

brain boner 

just like real ones, they can be given or received.

Tauni gave me a huge brain boner this afternoon.

brain boner by TauntaunandJ January 19, 2018

rainboner 

getting a boner because you're attracted to rain

Oshit! I just got a rainboner. The rain is so sexy today.

rainboner by parkyujin April 14, 2017