Green’s Dictionary of Slang

a lavatory, a privy; also attrib.

1665		Head Eng. Rogue I 123: Fearing I should catch cold, they out of pity covered me warm in a Bogg-house.
1675		Head Art of Wheedling 297: Throwing them into the Bog-house.
1689		General Account Book Oct. 1689–Oct. 1690 in Cal. of the Inner Temple III: To Browne, the watchman, for burying the old man that kept the bog-house, 16s [F&H].
1696		Motteux (trans.) Pantagruelian Prognostication (1927) II 690: Those who are troubled with the through-go-nimble, or wild squirt, will often prostitute their blind cheeks to the bog-house.
1705		E. Hickeringill Priest-Craft II 48: There is no better place for his nasty Guts [...] then in the Jaques, the Bog-house or House of Office.
1713		W. King York Spy 70: The emptying a Bog-house cou’d not have surpriz’d our smell with a more intolerable Nosegay.
1726		Art of Meditating over an House of Office 8: Others [...] will regard it only as a piece of Banter; having, perhaps, never before, heard of Soothsaying in a Boghouse.
1739		R. Bull Grobianus 266: It gave so rank, so redolent a Smell, As wou’d a Boghouse or a Jakes excel.
1744		‘Jeffrey Broadbottom’ Meditations Upon an House-of-Office 22: What is thy Shop O Jacob! but a Bog-House, fill’d with nothing but Bum-Fodder.
1754		Scoundrel’s Dict. 15: A Bog-house – Croping-ken.
a.1760		‘Hurlothrumbo’ Bog-house Misc. v: I have even found some of the Spectator’s Works in a Bog-house, Companion with Pocky-Bill.
1779		J. Gillray Sawney in the Bog-House [cartoon title] 4 June.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: bog house the necessary house.
1811		Lex. Balatronicum.
1826		Dublin Eve. Mail 1 May 1/5: To the highest bidder [...] Monegleigh, including the Bog-house and Garden thereof.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1873		Sl. Dict.
1888–94		‘Walter’ My Secret Life (1966) I 34: The boy took the key and went to the bog-house (no water-closets then).
1921		Western Mail (Perth) 3 Feb. 5/1: I was once consulting a carter about the use of bog-house-soil, upon a piece of cold, iron clay, on which nothing would grow, when the fellow turning up his nose most delicately, told me, he hoped I would then get people proper for the employ.