Having an orgasm at the mere mention or thought of something.
I had an instagasm when I saw your hot mom naked.
Giving an instant orgasm by quickly jabbing one's sides near the kidney on one or both sides at once which causes involuntary movement and sometimes unnecessary noises...
Boy 1: I'm going to give that kid an insta-gasm guys...
Boy 2: (After he was given the insta-gasm) (yelling) IT'S SO INSTANT!
1) Verb: To instantaneously and uncontrollably jizz in one's pants upon the thought, mention, sight, presence, brief musings, discussion, pondering, or stalking of a person, place where person hangs out, or thing the person likes, loves, or maybe looked sideways at.... or maybe he or she just thinks about it... maybe... you will find out.... you must find out!
2) Noun: An act of instantaneously, and uncontrollably jizzing in one's pants as a result of the aforementioned reasons.
Girl 1: So I heard you saw Terry Hatcher yesterday.. She's so pretty!
Girl 2: OMG yeah I know, my ex-boyfriend always used to tell me how she was such an instagasm (it's part of why we broke up, can't have my man chasing another woman).
Girl 1: What's an instagasm?
Girl 2: Look it up on urban dictionary, duh!
An instant orgasm by seeing something or even by the mere thought of something.
Meekey: Dude, did you see that girl wearing a beanie?
Atom: Yeah man. It was like an instagasm.
When you see something or feel something that causes one or more of your senses to orgasm.
Guy 1: *Sees extremely hot girl* *Insta-gasm*
Guy 2: *Eats bacon* *Insta-gasm*
Guy 3: *Hot drunk girl falls on top of him* *Insta-gasm*
we were going at it, and before he put it in, he instagasmed and went to sleep.
the practice of urinating or taking a shit upon ones self after being exposed to a frightening image.
Dont instagasm when I show you the pic that I took of my mom nude. Unless you're into that kinda thing.