look up any word, like blumpkin:
A Fantasmagasm happens when something is really, really awesome. Not necessarily sexual. It consists of an immediate smile and jumping up and down in giddy fashion going "Omg! That's so awesome!" or something to that effect. It is pure happiness and excitement.
When I told Johnny he won the lotter he had a fucking Fantasmagasm!
by Macdaddy41 August 26, 2007