Definition & Meaning of "rump ranger"in English

What is the origin of the term "rump ranger" and how is it used?

Rump ranger is a slang term that appeared in mid-20th-century English to mock a man for engaging in anal sex. The term combines "rump," a crude word for the buttocks, with "ranger," suggesting movement or activity, literally implying someone who "ranges" over another's buttocks. Historically, it was derogatory and insulting, used to ridicule or demean men for sexual behavior. Today it remains vulgar and offensive, generally limited to informal, mocking, or sexualized contexts rather than polite or neutral conversation.