Green’s Dictionary of Slang

1. (also splicing) the act or institution of marriage.

1805		J. Davis Post Captain (1813) 30: What an infernal splice! What a damnable sacrifice!
1843		Bellew Memoirs of a Griffin II 31: ‘It’s all up with him,’ said the caustic old bachelor captain [...] ‘as dead a case of splice as I ever saw’.
1855		Delhi Sketch Bk 1 Jan. 3/1: [H]e acted the part of a fond Papa, / When the splice came off.
1862		Cornhill Mag. Jan. 54: But till the splice is made she’s a right to please herself .
1876		J.G. Holland Sevenoaks 303: I’m a little interested in her myself and I’m going to pay for the splice .
1900		Marvel 6 June 15: It’s Blinker’s silver splicin’.
1999		Guardian Weekend 3 July 53: Five couples who have toppled like twentysomething dominoes to the old Splicing Machine.

2. one’s wife.

1830		J. Galt Lawrie Todd I Pt II 91: That ’ere young woman, my niece – she ben’t five-and-twenty – she’ll make a heavenly splice!
1840		T. Haliburton Clockmaker III 101: And there sets his young wife [...] a-watchin’ of him. Ain’t she a heavenly splice, that?
1864, 1867, 1870		Hotten Sl. Dict.