Green’s Dictionary of Slang

1. a lowdown drinking tavern where thieves and beggars could bring poached animals to be roasted.

1612

Dekker O per se O L3: This killer brings to the slaughter-house of the Diuell (viz. a Bowsing Kenne) a Bleating Chete, (a Sheepe).

2. a crooked, rapacious gambling house or casino.

1809		Sporting Mag. XXXIII. 73: The houses called by sharpers Slaughter-Houses, are those where persons are uniformly employed by the proprietors to affect to play at hazard for large sums of money.
1832		Satirist (London) 29 Apr. 143/1: Pickering-place, which opened as a [...] slaughter-house, that is, none but flats to be introduced and those to be totally stripped.

3. a shop where goods are bought from small makers at very low prices.

1861

(con. 1840s–50s) H. Mayhew London Labour and London Poor I 333/1: The wretchedly under-paid and over-worked shoe-makers, cabinet-makers and others call these places ‘slaughterhouses,’ when the establishment is in the hands of tradesmen who buy their goods of poor workmen.

4. (Und.) a hospital.

1882

‘The Jargon of Thieves’ in Derry Jrnl 8 Sept. 6/6: A hospital for the wounded [is called] ‘a slaughter-house’ .

5. a factory paying very low wages.

1902

H. Baumann Londinismen (2nd edn).

6. a cheap brothel.

1972		R.A. Wilson Playboy’s Book of Forbidden Words.
1986–7		Maledicta IX 148: The compilers ought to have looked farther afield and found: […] slaughter house.