rat on
phrasal verbrat on somebody
(North American English also rat somebody out (to somebody))
- (informal, disapproving) to tell somebody in authority about something wrong that somebody else has done
- Where I come from, you don't rat on your friends.
rat on something
- (British English, informal) to not do something that you have agreed or promised to do synonym renege
- The government is accused of ratting on its promises to the unemployed.