Most likely the final negatory answer you get after saying "Please" two or three times in a row. It's better to just give up, because when you hear this, whatever you want is not gonna happen.
You: Can we get that (insert name on expensive, useless piece of junk)
Me: No.
You: Please?
Me: No.
You: Please!
Me: No!
You Pleeeease?
Me: Told you before, not gonna happen!
by werallsonsofbitches December 17, 2009
When someone is telling you something will happen and is trying to say it in a meaningful matter, usually used in sports.
Londell will go outside and shits gonna happen
by rubey rube October 22, 2009
A sarcastic statement used to mock someone's bad idea, pretty much saying it's not gonna work out like that.
Kid 1: "Oh man, my friend and I are gonna go get loaded it in the park!"

Kid 2: "Oh, well, I mean, the police station is right next door... But yeah, no, that's totally gonna happen."
by Peter W.N. June 28, 2009
A day for couple that will 100% flop to give it a shot.
Person 1: Sophia and Blake will never last
Person 2: oh yea! but they should date on november 7th! National Not Gonna Happen Couples Day
by ship it November 5, 2019