A 1-5 is a code name for a male that's affiliated with the street gang, the "15 Block Gangsters". A 4-5 is a code name for a female that's affiliated with the "15 Block Gangsters". The 4-5 comes from their call to greet each other saying, "1-5 1-5, 4-5 4-5".
by Skreetz December 20, 2018