south of the border
Ⅰ
1. adjective
unacceptable. Glasgow rhyming slang for OUT OF ORDER. Not a reference to England but (thanks to Hollywood) Mexico UK: SCOTLAND, 1988
2. adverb
in or to the area of the genitals, especially a woman's US, 1945
Ⅱ ⇨ south of the border; south
noun order; an orderly condition. Glasgow rhyming slang UK: SCOTLAND, 1988