1. [late 19C+] (orig. US, also bul, a police officer; thus US tramp) bull buster, one who is obsessed with assaulting the police; fresh bull, a police officer who cannot be bribed; wise bull, a detective.
2. [20C+] a railroad security guard.
3. [20C+] (US prison) a prison warder; thus night bull, the night guard.
4. [1910s+] (US) a detective.
5. [1910s+] in comb., a certain kind of police officer, e.g. country bull, a local, small-town officer; narcotic bull, a Federal narcotic officer; motorcycle bull, motorcycle police officer; road bull, highway patrol officer.
see separate entries.
[1930s–60s] (US tramp) frightened of the police.
[1910s] (US tramp) a police van used to transport prisoners, a Black Maria n. (1)
1. [19C] (US Und.) one who impersonates an official in order to extort money.
2. [1930s+] (Aus.) a villain who impersonates a police officer and preys on couples in lover’s lanes, extorting money from those who should not, for whatever reason, be there.
[1970s] (Aus.) a vehicle carrying suspects or criminals to a police station or prison.