The thing you say when you have nothing else to say.
Frank:"FUCK YOU KYLE"
Kyle:"FIGHT ME YOU ITALIAN FUCK"
all purpose statement that is used when you disagree with anything anyone says or when you simply want to fight someone. Also used to express indifference.
john: hey jack, i hate your new shoes.
jack: fight me.
boy1: dude, do you want play football?
boy2: fight me