Jail bait: 1. Any person as a minor criminal, esp. a female with whom one makes an acquaintance at the risk of getting into trouble; specifically a woman of such compelling attractiveness that men will take to crime in order to furnish her wants. 2. Specifically an attractive girl who has not reached the legal age of consent;because having "carnal knowledge" of a minor is considered a major crime in most states.
Example: Hey Bruce, Homey and me heard you got some of that jail bait from down off the pier. Keep her away from us! You better watch yourself friend, before you know it you'll be pullin' three to five.
Clarification: hello there Bruce. Homer and I heard tell that you are keeping acquaintance with quite an attractive young girl who has not yet reached the legal age of consent. We ask that you please refrain from bringing her anywhere near us. You would do good to be closely observant of your behavior in this matter or before you even have time to become aware of it you will be serving a sentence of approximately three to five years in a penitentiary institution.