Definition & Meaning of "butt munch"in English

What is the origin of the term "butt munch" and how is it used?

Butt munch is a slang term that appeared in mid–20th-century English to describe a contemptible or obnoxious person. The term combines "butt," referring to the anus, with "munch," meaning to eat or gnaw, creating a crude image intended to insult or humiliate. Literally, it doesn't describe an action the person actually does—it simply uses the imagery to convey disgust or contempt. Historically, it was derogatory and vulgar, used to ridicule or demean someone, and today it remains informal, offensive, and insulting, typically appearing in casual or mocking contexts rather than polite conversation.