supergrass

listen to the pronunciation of supergrass
الإنجليزية - الإنجليزية
An informer providing substantial quantities of information on criminal or terrorist activities to the police

Australian Phillip Inglis is an infamous supergrass.

A supergrass is a person who gives the police information about a large group of criminals. a criminal who gives the police information about many other criminals, in order to get a less severe punishment
a police informer who implicates many people
supergrass
المفضلات