supergrass
su‧per‧grass /ˈsuːpəɡrɑːs $ -pərɡræs/
noun [countable]
British English informal a criminal who gives the police information about many other criminals, in order to get a less severe punishment
su‧per‧grass /ˈsuːpəɡrɑːs $ -pərɡræs/
noun [countable]British English informal a criminal who gives the police information about many other criminals, in order to get a less severe punishment