|1.||keep your left up|
1.A basic rule in street fighting to gaurd against an attack from someone's right hand.
2.Euphemistically to take precaution against expected obstacles.
1. Yo son you wann eff w/ me he better keep your left up that's my word.
2. You making that run on the fourth? Yo, you betta keep your left up the feds be creeping!