cheese eater

noun

, Slang.

1. an informer; rat.
2. a person who betrays, denies, or abandons their associates, social group, beliefs, etc.

Word History and Origins

Origin of cheese eater¹

An Americanism dating back to 1870–75; the sense “informer”; in association of cheese with rat

Example Sentences

“But Buchalter was no cheese eater and wouldn’t squeal. On March 5, 1944, he went like a mensch to ‘Old Sparkie’ in Sing Sing.”

From New York Times

That’s roughly your situation as a cheese eater in America, where the cheeses we eat are all pasteurized, an unnecessary treatment that kills flavor along with germs.

From Time

A "cheese eater" is an informant.

From Wall Street Journal

Cheese The Cypriot is a great cheese eater.

From Project Gutenberg