Green’s Dictionary of Slang

Newgate, thus any prison.

1718		C. Hitchin Regulator 19: The Rumboe alias, Whit, alias Newgate.
1725		New Canting Dict. n.p.: rumbo a Prison or Gaol.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
1768		(con. 1710–25) Tyburn Chronicle II in Groom (1999) xxvi: The Rhumbo, or the Whit Newgate.
1786		Whole Art of Thieving n.p.: The rumbo, or the whit newgate.
1796		Grose Classical Dict. of the Vulgar Tongue (3rd edn) n.p.: Rumbo. [...] a prison.
1811		Lex. Balatronicum [as cit. 1796].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
c.1850		Duncombe New and Improved Flash Dict.
1859		Matsell Vocabulum.
1867		Nat. Police Gaz. (NY) 14 Sept. n.p.: There is now in ‘rumbo’ here awaiting trial for various offences, a collection of the most desperate characters that ever graced prison walls.