Collins COBUILD Advanced Learner's English Dictionary - back-seat driver

also backseat driver (back-seat drivers) 1. If you refer to a passenger in a car as a back-seat driver, they annoy you because they constantly give you advice. N-COUNT c darkgreen]disapproval 2. If you refer to someone, especially a politician, as a back-seat driver, you disapprove of them because they try to influence a situation that does not concern them. They accused the former prime minister of being a backseat driver. N-COUNT c darkgreen]disapproval