1. [late 18C+] (orig. UK Und.) a street or streets as walked by a prostitute.
2. [early 19C+] (orig. UK Und.) one’s own area of activity, operation.
3. [mid-19C] (UK Und.) an area in which a pickpocket works.
4. [mid-19C] (UK Und.) the area patrolled by a watchman.
5. [1900s–60s] (US prison) that area in which a criminal gang operates, thanks to bribing a local politician/police department.
6. [1930s] an area where drugs are sold on the street.
7. [1940s+] (Aus.) the area patrolled by a sheep or cattle musterer.
[1970s+] (Aus. gay) to frequent an area in search of a sexual partner.
[1900s–10s] (mainly Aus.) drifting away from the subject in hand, out of one’s usual routine.
SE in slang uses
[1950s] (UK juv.) a police officer.
[1940s+] a policeman.