sprat, n. — Green’s Dictionary of Slang

sprat n.

also spratt

[its diminutive size, like that of the fish]

1. a sixpence.

1839		H. Brandon Dict. of the Flash or Cant Lang. 165/2: Sprat – sixpence.
1847		G.M.W. Reynolds Mysteries of London III 66/1: Tim sent the yack to church and christen but the churchman came to it through poll, as Tim’s shaler had slummed on him a sprat and an alderman last week.
1857		J. Archbold Magistrate’s Assistant (3rd edn) 444: Sixpence, downer, also sprat.
1867		J. Greenwood Unsentimental Journeys 41: As the youth had mentioned two threepences as equivalent to a ‘sprat,’ it was pretty clear that the name of the familiar little fish was ‘Shoreditch’ for sixpence.
1879		‘Autobiog. of a Thief’ in Macmillan’s Mag. (London) XL 501: I got three and a sprat (3s. 6d.) an ounce [of silver].
1881		Morn. Bulletin (Rockhampton, Qld) 18 July 2/6: For our next coin in value [i.e. sixpence] twenty names are found [...] ‘Fyebuck,’ ‘half-hog,’ ‘kick,’ ‘lord of the manor,’ ‘pig,’ ‘pot,’ ‘say saltee,' ’sprat,’ ‘snid,’ ‘simon,’ ‘sow's baby,’ ’tanner,’ tester,’ and ‘tizzy’.
1884		Leicester Chron. 28 June 12/5: I’ve got lists of everybody in London good for a sprat, and that’s the best cadging dockyment I ever seen.
1886		W. Newton Secrets of Tramp Life Revealed 9: Sprat ... Sixpence.
1889		Dead Bird (Sydney) 28 Sept. 4/3: ‘I paid a sprat for one [i.e. a newspaper] last week’.
1893–5		H. Lawson ‘Two Sundowners’ in Roderick (1972) 101: Do yer think I want yer blarsted money? [...] When did I ever ask yer for a sprat?
1903		J. Furphy Such is Life 93: I’d part my last sprat to that feller.
1910		Bulletin (Sydney) 15 Sept. 38/2: And ‘Salvation’s’ in the filling of a hat / When it’s clerical of cut, and handed round / With a deftness which takes in the tray and sprat.
1921		(con. WWI) E. Lynch Somme Mud 6: A man holds up a [...] sprat and the coon forces the piece [of food] down and is sixpence richer.
1931		‘Eng. Und. Sl.’ in Variety 8 Apr. n.p.: Sprat or sprazzy—Sixpence.
1938		J. Curtis They Drive by Night 65: Ought to have asked for seven and a sprat.
1941		V. Davis Phenomena in Crime 253: Dieners. Shillings. Sixpence and three-penny bit called ‘sprats’.
1950		P. Tempest Lag’s Lex. 199: spratt. Sixpence.
1959		I. & P. Opie Lore and Lang. of Schoolchildren (1977) 175: Sixpence is a ‘kick’, ‘sprat’, or ‘tanner’.
1976		(ref. to 1940s) R. Barnes Coronation Cups and Jam Jars 133: The bloke produced the lowest silver coin of the realm [...] Dad’s eyes bulged with contempt. ‘A sprat,’ he said, with hatred.

2. (Aus. Und.) a six-month prison sentence.

1950

S.J. Baker in Sun. Herald (Sydney) 8 June 9/3: Slang words for sentences of various lengths include: ‘deuce,’ two months; ‘drag,’ three months; ‘sprat,’ six months; ‘the clock,’ twelve months; ‘spin’ or ‘full hand,’ five years; ‘brick,’ ten years; ‘the lot,’ life imprisonment.

3. (Aus.) a child.

2019		P. Temple ‘High Art’ in The Red Hand 36: ‘They’ve sent their sprogs to bloody Ormond and Trinity’.
2023		R. Milward Man-Eating Typewriter 74: [W]aiting for their seven sprats to return from boarding skol.

SE in slang uses

In compounds

sprat day (n.) [the first day of the sprat season]

9 November, i.e. the Lord Mayor’s Day, when the new Lord Mayor of London takes up his office.

1873		Bradford Obs. 24 Dec. 7/5: The 9th of November (Lord Mayor’s Day) is accordingly by costermongers sometimes called ‘Sprat Day’.
1894		Buckingham Exp. 24 Nov. 3/6: The 9th of November is the day on which the new Lord Mayor tales up his office [...] it is the beginning of the sprat season, and hence its popular name of Sprat Day.

sprat-trap (n.) [simple image of eating rather than size]

the mouth.

1823

Westmoreland Gaz. 7 June 1/5: Titus planted a punch upon Abrawang’s sprat-trap.