Troyerr wrote Acronym for You Only Live Once. Mainly used to defend doing something ranging from mild to extreme stupidity.

Mild stupidity:

Friend: Dude, you probably shouldn't smoke that joint you found on the ground.
Me: **** it, YOLO.
Extreme stupidity:
Friend: Dude, you probably shouldn't be posting random definitions on urbandictionary while you're stoned.
Me: **** it, YOLO. .

That was an example of the term 'YOLO' I Think this terms is overused far to much..its like saying if you jump of a building high enough to kill you , you die.
it states the obvious and its just stupid.

RANT OVER.

dude your dumb as POO! YOLO stands for you obviously love oreos. *trollface*