Green’s Dictionary of Slang

1. a jockey, thus jockette.

1826		Sporting Mag. XVIII. 385: A neat horseman, and quite at the top of the tree amongst Northern jocks .
1845		Bell’s Life in Sydney 11 Oct. 4/3: He [i.e. a race horse] was met by those who came in pursuit, and was again mounted by his jock [...] We have no doubt that Mr. Forth intended to win with Doleful, and instructions to that effect were given to the jocks.
1849		Era (London) 3 June 3/4: They must clap a fust-rate jock on his back, or I’m off the bargain.
1859		G.F. Atkinson Curry & Rice (3 edn) n.p.: Our Griff his his own jock [...] one Pyjamer, an Oriental breaker-in of horses.
1856		‘The Druid’ Post and Paddock xii. 211: Many clever young jocks [...] who go everywhere, have ridden as many races by the time they are twenty .
1858		Bell’s Life in Sydney 13 Nov. 3/2: The celebrated jock, Cory, led in Joe.
1874		‘Old Calabar’ Won in a Canter I 54: Which shall you declare to win with?’ asked the sly-looking little man [...] ‘Oh, with Guardsman,’ said George. ‘And your jocks?’ put in another. ‘All the talent is engaged’.
1881		A.C. Grant Bush-Life in Queensland II 70: The bell rings—the jocks are weighed; and as it rings again they make their way to the post.
1884		H. Smart Post to Finish II 237: I’m aware, of course, that I am called the ‘Aristocratic Jock’.
1890		Sporting Times 1 Mar. 2/3: I’m no plunger, / But I’ll gamble the whole of my stock; / That there isn’t a horseman can beat him, / Be he gentleman rider or jock.
1894		Truth (Sydney) 25 Nov. 6/2: Liddiard is a cut above the ordinary pony jock.
1896		F. Hutcheson Barkeep Stories 84: ‘Now, gimme twenty t’ bet fer de jock’.
1901		‘Rolf Boldrewood’ In Bad Company 394: A fine horseman and steeplechase jock.
1901		Sydney Sportsman (Surry Hills, NSW) 20 Mar. 1/3: The same Patrick is one of the best pony jocksters extant.
1906		Sun (NY) 9 Sept. 3/2: He was scrawling the names of the jocks on his programme.
1910		Sun. Times (Perth) 23 Jan. 4/3: A buggy drove up to the door, containing an unregistered jockster and one of his ‘horsey’ companions.
1911		Truth (Brisbane) 9 July 3/2: ‘No more dead uns for me,’ said a jockster to a brother pigskin artist recently.
1912		Conan Doyle Lost World 85: ‘Sir John Ballinger is the best gentleman jock in the north country’.
1912		Bulletin (Sydney) 12 Sept. 2/4: The stewards invariably perform this act in the case of any lad who gets a bit above himself – which accounts for the circumstance that the British jock [...] is about the most humble, self-abasing, forelock-dragger on God’s green earth.
1922		T.A. Dorgan in Zwilling TAD Lex. (1993) 16: Yes, yes, yes, but listen to me — I got this from the jock himself — This is in the bag.
1938		D. Runyon ‘The Lemon Drop Kid’ in Runyon on Broadway (1954) 372: He is a brother of Sonny Saunders, the jock.
1943		H.A. Smith Life in a Putty Knife Factory (1948) 151: Jocks [...] are strange people.
1953		R. Chandler Long Good-Bye 298: The fix can be in any time somebody says so. There’s only one way a jock can win a race, but there’s twenty ways he can lose one.
1968		W.S. Hoffman Loser 59: The race is important to Doug Richard, Whisper Jet’s rider [...] Richard’s a good jock.
1974		G.V. Higgins Cogan’s Trade (1975) 96: He knows everybody, the jocks, the hot-walkers, everybody.
1984		W. Murray Tip on a Dead Crab 217: Watch this dumb move the jock makes on Machismo [...] Look at that! You ever seen a dumber rider.
1984		Benjamin & Pearl Limericks Down Under 68: A jockey from Cunnamulla / Met a jockette from Ulladulla.
1999		Guardian Media 2 Aug. 16: Racing cannot come to terms with this. [...] Mrs Cecil and her shock jock have disturbed the natural order of things.
1999		P. Temple Black Tide (2012) [ebook] Their dad was a jock, got too big.

2. in attrib. use of sense 1.

1847

Bell’s Life in Sydney 25 Dec. 2/3: A riglar out-and-out, down-the-road, up-to-a-trick-or-two, half-jock-half-jarvey coat.

3. (US) an autombile driver.

1917

Cincinnati Enquirer (OH) 12 May 12/2: ‘I lamps a big limo [...] The jock wuz asleep’.

4. (orig. US) a disc jockey.

1947		in Tomorrow Aug. 27: ‘A list of jocks and record reviewers’ – jocks being disc-jockeys or conductors of the record-playing programs on the radio [HDAS].
1952		Associated Press 2 Dec. in Wentworth & Flexner DAS (1975) 294/1: Already the jukes and jocks are dinning our ears with Christmas songs .
1961		H. Ellison ‘This Is Jackie Spinning’ in Gentleman Junkie 69: The Conlan [record] gets the big push from this jock!
1974		V.E. Smith Jones Men 180: The girl was [...] half-listening to the eight-to-midnight jock on WBSB.
1984		C. White Life and Times of Little Richard 67: We relied on the jocks to push the records.
1997		Simon & Burns Corner (1998) 172: Fran [...] curses the radio jock for talking too much.
2000		Indep. Rev. 16 Mar. 11: Radio 1 was falling over itself to show massive respect to its top jock.

5. (US) a worker, an operator, e.g. construction jock, elevator jock [abbr. jockey n.² (4b)].

1967		E. Shepard Doom Pussy 15: The helicopter jock from Little Rock.
1972		E. Shrake Strange Peaches 166: The motorcycle jocks never went to the drive-in cafés many of us frequented.
1989		K. Dunn Geek Love 57: Even this scummy old station jock was noticing.
2000		Indep. Rev. 14 Jan. 14: The depot-jocks stared at his e-mail.