When someone wraps their legs around another, locking them between their legs and body. This term is mainly used in a sexual sense.

lil mad is like big mad but the opposite, you mad but not mad to the extent of pullin somthin

When a woman wraps her legs around a guys neck and puts him in a chokehold while he eats her out.

A leg lock is a slow painful death to the running man. You're the runner, one leg is forward and the other is back there somewhere and you've just got to get away but before you get a chance that guy/gal slides on the ground underneath you and figure fours their leg around your straight back leg. You flip around to kick it off as their legs are closing in on yours and snap.. you don't know if it's broken, you don't know if it's out of it's socket. You're gimpy. You should probably see the doctor but you're afraid you'll look like a pussy. It's okay bruh, but seriously if it's not better in three days go see a doctor.