Definition & Meaning of "slam-pig"in English

What is the origin of the term "slam-pig" and how is it used?

"Slam-pig" is a slang term used to describe a woman regarded as promiscuous and unattractive. It likely emerged in English in the 20th century as a crude and insulting metaphor, combining "slam" (suggesting aggressive or careless sexual behavior) with "pig" (an animal long associated with filth and gluttony) to attack both appearance and morality. The term is strongly derogatory, used in informal, hostile, or vulgar contexts, and is intended to shame or demean the woman it targets.