Green’s Dictionary of Slang

1. sado-masochism.

1965		Guild Dict. Homosexual Terms 40: s and m (n., adj.- hyph.): Sadism and Masochism. Used in describing: ‘an S-and-M bar’.
1976		Time 5 Apr. 61: Porn-film makers long avoided ‘S-M’, as it is known in the trade, because they were convinced that it would drive away customers.
1978		L. Kramer Faggots 61: Fucking and being fucked and light s & m.
1988		P. Califia Macho Sluts 40: My first experience with S/M was with Sue.
1993		K. Lette Foetal Attraction (1994) 63: English dinner parties are a form of S & M. Sado-mastication.
2000		Guardian Rev. 14 Jan. 5: They go in for some serious S&M.
2003		K. Cage Gayle 92/1: S/M n. (abbr.) and v. • n. (abbr.) sadomasochism [Classified advertisements] (also S&M).

2. a sado-masochist.

2001

K. Waterhouse Soho 87: Wunner them, eh. S & M.