1. Police code for a person that is a danger to him/herself.
2. Often used by gangster and thugs as a person that is psycho enough to put his/her or anyone else's life on the line.
3. Can be a reference to a trance like episode were the person doesn't care about the law, life or anything around.
1. "I'm going to need assistance with a 51 50 on 12th st." - officer Doofy
2. Miss 5150 is a hot piece but I heard that she is straight up psycho and she is down for that BLU flag.
3. That slob better quit clowning or I'm going to have to go 51 50 on his ass.