Green’s Dictionary of Slang

jockey n.2

1. [late 18C–mid-19C] a man.

2. [mid–late 19C] (UK Und.) the expert, the exemplar.

3. any form of worker.

(a) [mid-19C–1940s] an accomplice or assistant, usu. of a driver of a cab or utility vehicle.

(b) [mid-19C+] a worker in a particular job, e.g. swab jockey, washer-up, pump jockey, petrol pump attendant, grunt-and-squeal jockey, a stock hauler, juice jockey, a gasoline-truck driver, suicide jockey, a nitro-glycerine hauler, disc jockey.

(c) [1910s+] any form of driver, esp. of cabs, buses.

4. [late 19C] (Aus.) a tramp who illegally rides freight trains.

5. [1900s–30s] (US Und.) a horse thief.

6. [1930s] a pimp.

7. [1930s] (UK Und.) a gang member.

8. [1930s+] a whore’s client.

9. [1940s+] (US) in homosexual uses.

(a) a homosexual tramp.

(b) a masculine lesbian.

10. [1950s] (gypsy) a general term of address, e.g. Hello jockey.

11. (UK Und.) a policeman.

12. [1950s–70s] a user of drugs or one who is habituated, e.g. hop-jockey, drug addict, horse-jockey, heroin user.

13. [1970s] (US) a male sexual partner.

14. [1990s+] (Irish und.) a sex offender, a rapist.

In compounds

jockey’s breakfast (n.)

[1990s+] (Irish) sexual intercourse and a slice of bacon.