Green’s Dictionary of Slang

(UK society) married.

1853		G.J. Whyte-Melville Digby Grand (1890) 126: I found myself relapsing in society into the grade of an ‘engaged man’ [...] and one or two intimate friends [...] begged to know when I was to be ‘turned off.’.
1863		T. Taylor Ticket-Of-Leave Man Act III: I’ll drive to the bank — cash this — settle with those counter-skippers, and rattle back in time to see you turned off.
1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 324: Her sister’s to be married to-morrow, and we’re all going to see her turned off.
1890		Kipling ‘The Story of the Gadbsys’ in Soldiers Three (1907) 164: I’ve seen a few turned off before, but never one who went to the gallows in this condition.
1902		Bulletin (Sydney) 4 Oct. 13/3: After his mate had been turned off, at a private house in Fitzroy, that gentleman turned to him and said, ‘It’s your turn now. Go ahead; I’ll pay the fee.’ He was thereupon married to the bridesmaid, whom he had never seen before.