Green’s Dictionary of Slang

1. (US) whipped, flogged.

1859

Matsell Vocabulum.

2. subjected to sexual intercourse.

a.1800		Records of the Beggar’s Benison 84: Why is an old man’s wife like a hot bun? – Because she wants to be well butter’d.
1888–94		‘Walter’ My Secret Life (1966) II 246: The more a cunt’s buttered, the better it grinds.