non toi

The word non toi means no u in French. It is pronounced "non twa". Like the word no u, it is a comeback that you use in a situation where you are losing/bad situation.

Person 1: Omg you look sooooo ugly today! Get a life!
Person 2: Non toi
Person 1: Ugh! That doesn't even make sense! What does that mean anyway?
Person 2: It means no u you uncultured noob
Person 1: Instant death