Green’s Dictionary of Slang

1. (US) a brothel.

1851		Western Police Gaz. (Cincinnati, OH) 29 Mar. n.p.: At a certain boarding house [...] a young lady (she disgraces the name) in company with one or two ‘Auction pimps’ [etc].
1866		Night Side of N.Y. 40: A midnight descent has just been made upon a ‘moll crib’ as he calls the ‘boarding house’ of the portly dame.
1904		Sydney Sportsman (Surry Hills, NSW) 12 Oct. 8/6: A well-known ‘boarding-house’ in Paddington sports a framed text [...] to tell visitors that, ‘Man wants but little here below, nor wants that little long’.
2001		(con. late 19C) C. Jeffords Shady Ladies of the Old West 🌐 Cattle towns, mining towns, railroad towns, and towns near military installations [...] invariably had a sufficient number of girls to warrant a ‘line,’ a ‘maiden lane,’ a ‘boarding house’ or two.

2. a prison; thus boarder, a prisoner.

1859		Matsell Vocabulum 13: boarding-house City prison; the Tombs.
1861		Bell’s Life in Sydney 1 June 3/2: Their worships [...] gave them permission to take up their quarters at the National boarding-house at Darlinghurst for three months.
1874		N.O. Republican (LA) 24 May 5/4: Nash had us taken to the boarding house prison; kept us there some time.
1881		Trumble Sl. Dict. (1890).
1887		L.A. Dly Herald 24 June 7/2: The gentleman of color showed fight and the officer was compelled to call for assistance before the dusky angel could be persuaded to move towards the city’s boarding house. At the prison he gave the name of Geo. Hawkins.
1895		Crowe Aus. Sl. Dict. 10: Boarding House, a jail.
1898		Salt Lake Herald (UT) 19 Jan. 1/2: Mrs Mary Hampton applied for the position of matron of the city jail [...] the applicant to have the free use of the entire prison boarding house.
1910		Sun. Times (Perth) 5 June 2nd sect. 13/4: The present number of ‘boarders’ lodging in the Fremantle donjon-keep is about 170.
1927		‘Jargon of the Und.’ in DN V 439: Boarding house, Specifically the Tombs prison, by extension, any prison.
1931		Irwin Amer. Tramp and Und. Sl. 32: Boarding house.—Originally applied to the Tombs, New York’s City prison, the term has become known as the popular reference to any city prison.
1949		Monteleone Criminal Sl. (rev. edn) 29: boarding-house man A prison cook.