Green’s Dictionary of Slang

jack sprat n.1

[the name survives mainly in the nursery rhyme, which itself post-dated it: its first appearance in print was 1570, while the nursery rhyme was first published in 1639]

a small person, a dwarf.

[UK]Marriage of Wit and Science V v: But what, no force ye are but Jack Sprot to mee.
[UK]J. Ray Proverbs 211: Jack Sprat he loved no fat.
[UK]B.E. Dict. Canting Crew n.p.: Jack-sprat, a Dwarf, or very little fellow, a Hop-on-my-thumb.
[UK]New Canting Dict. [as cit. c.1698].
[UK]Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]Lex. Balatronicum.
[UK]‘Thomas Brown’ Fudge Family in Paris Letter III 28: There never was seen such a race of Jack Sprats.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]Manchester Courier 29 June 2/3: The little knowing-looking cockney orator, who they call Jack Sprat.
[US]Matsell Vocabulum.
[UK]E. de la Bédollière Londres et les Anglais 315/2: jack sprat, petit homme.
[UK]Sl. Dict.
[US]Trumble Sl. Dict. (1890).