Green’s Dictionary of Slang

one of a variety of sexual acts, e.g. masturbation between the female breasts; urinating into the anus; licking semen from the anus.

2003		Urban Dict. 4 Apr.. 🌐 Pugwash: A tit wank (Australian).
2005		Urban Dict. 20 Sept. 🌐 Pugwash: When one licks the semen out of an arse after coming in it.
2007		L. Redhead Cherry Pie [ebook] She could come up with some filthy stuff [...] I’ll never forget the night she explained the definition of pugwash. Gross!’.
2010		Urban Dict. 20 Sept. 🌐 Pugwash: To urinate into another persons anus.