n. An intense rush of intellectual fervor or excitement in response to a stimulus such as recognizing a literary allusion in "The Simpsons" or finally understanding how to do that advanced calculus problem or even just anything really cool. Usually accompanied by inability to formulate actual words and an intense enthusiasm about the subject that induced the braingasm.
That geek had the biggest braingasm after she saw LotR:RotK.
the pleasant, clearing, "orgasm-like" feeling your head and sinuses experience after a hearty sneeze.
I had a braingasm when I sneezed.
(n) a subtle pleasure expressed when the brain is exposed to stimulating discussions. Such non-sexual pleasure, bonds the people taking part in it. This activity often occurs between Bibi and Chouchou.
Oh my gods; the discussion we had about the human condition last night gave me a braingasm bibi.
A pleasurable tingle one experiences on the scalp. Has other meanings
She had a braingasm when she thought about candy.
When you find out some unknown piece of information, and you feel a rush of Intellectual glee. Related to intellectual masturbation, and Brain Jizzing
When Brian read the theory on equilibrium, he had a Braingasm
An orgasm of the brain, something that would be the equivalent of information sex, something that would make a nerd smile in a kind of creepy, happy way.
Nerd 1: Dude, we just got our new Calculus books!
Nerd 2: Alright! Braingasm!
Nerd 1: Yeah, we're so cool
That which causes a braingasm.
That was braingasmic.