An expression used to challenge a person to commit an action.
Appropriate responses are as follows:
In agreement to do the action = "Who Won't?"
Not in agreement to do the action = "You right"
Absolutely not in agreement to do the action = "Are you dumb?"
To counter challenge = "YOU won't!"
When used in an overly serious manor "you won't" may be interchangeable with "You will not!"
Warning: Increased use of alcohol can and will cause excessive repetition.
Person 1: "You won't do jam and night." Person 2: "Who won't?! YOU won't!"
The act of saying the phrase "YOU WON'T!" after someone announces they're going to do something. Generally used to be funny, and/or taunt the individual.
Whenever someone says they'll do something, someone else comes back with "You won't!" It's almost like a dare. If the person does said thing, the "You won't"-er usually comes back with something like "OK, so maybe you will."
Commonly used by the surf-bum kids who pioneered such gems of slang like "Dude" and "Sweet".
Person1: Man, every time my math teacher gives me homework, I want to pull a Columbine on her!
Person2: You won't!
(Person1 does. Person2 is arrested as an accessory.)
~OR~
Chemistry Teacher: Now, Hydrogen gas explodes very easily. I could show you a demonstration, but I don't have time.
Pyromaniac Class: You won't! You won't!
Chemistry Teacher: Well, I GUESS we could squeeze it in...