Green’s Dictionary of Slang

1. used to describe convicts who have been chained together for the purposes of moving them from one place to another, or on board a ship that transports them abroad; thus handcuffed together.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Persons chained or handcuffed together, in order to be conveyed to gaol, or on board the lighters for transportation, are in the cant language said to be married together.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].
1859		Matsell Vocabulum 53: married Two fellows handcuffed together.
1881		Trumble Sl. Dict. (1890).
1895		C. Crowe Aus. Sl. Dict. 48: Married, two prisoners handcuffed together.
1927		‘Jargon of the Und.’ in DN V 455: Married, Said of two men handcuffed together.
1931		Irwin Amer. Tramp and Und. Sl. 127: Married. – Handcuffed together.
1949		Monteleone Criminal Sl. (rev. edn).
1962		Ragen & Finston World’s Toughest Prison 808: married – Handcuffed together.

2. (US gay) in a homosexual relationship.

1726		Select Trials at Old Bailey (1742) III 37: I found between 40 and 50 Men making Love to one another, as they call it. They’d hug and play, and toy, and go out by Couples into another Room on the same floor, to be married, as they call it.
1931		Irwin Amer. Tramp and Und. Sl. 127: Married.- [...] Having unnatural sex relations.
1949		‘Swasarnt Nerf’ et al. Gay Girl’s Guide 18: The following words or phrases are frequently used, seriously or facetiously, in a sense the same as, or equivalent to, their meaning in straight English (Slang) [...] married.
1950		Goldin et al. DAUL 136/2: Married. (P) Bound by illicit or perverse sexual relations.
1962		Ragen & Finston World’s Toughest Prison 808: marry – To enter into homosexual relations [...] married – Having unnatural sex relations.
1972		B. Rodgers Queens’ Vernacular 131: married living together with another homosexual in a partnership of mutual consent.

3. (US drugs) of a drug, adulterated.

1957

El Paso Herald (TX) 3 Oct. 17/6: A few examples of [...] ‘calo’ [...] The term ‘married’ indicates opium in which foreign substances have been added.

4. (US campus) in a long-term relationship.

1989		P. Munro Sl. U.
1991		Eble Campus Sl. Fall.
1997		C. Newland Scholar 209: Marlena the bitch, tryin’ to set up her fuckin’ cousin with a married girl.