Green’s Dictionary of Slang

swished adj.

married.

1812		Vaux Vocab. of the Flash Lang.
1827		Egan Anecdotes of the Turf, the Chase etc. 183: The march to church of Sporting betsey and Gooseberry Jemmy to be swished.
1834		‘Mrs. Jones’ in Delicious Chanter 30: Joe and Sal Snooks had been svish’d that day.
1846		Swell’s Night Guide 64: For the old nark tumbled, that if his gal got swish’d, / ’Twould be all pickles, and then he’d be dish’d.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict. 252: SWISHED, or switched, married.
1881		Dundee Courier (Scot.) 13 May 7/6: Your wife? Why, you’re not regularly swished, are you?
1891		Sporting Times 18 Apr. 3/5: ‘Switched’ Married.