When someone is a backseat driver, they give unwanted advice or instructions to someone who's actually doing the task. The term comes from passengers sitting in the back of a car who constantly tell the driver what to do: “Slow down!” “Turn here!” “Watch out for that car!” Even though they're not driving, they act like they know better than the person behind the wheel.

You can find backseat drivers in many situations. During a group project, a backseat driver tells everyone what to do without doing much work themselves. When you're playing a video game, a backseat driver watches over your shoulder and shouts instructions: “Go left! No, jump now! Use that power-up!” It's especially frustrating because backseat drivers usually aren't responsible for the outcome; they're just making the actual doer more nervous and annoyed.

The word backseat itself simply means the rear seat in a vehicle, where passengers sit. When you hear someone talk about taking a backseat to something, they mean stepping back and letting others lead. A team captain who's injured might take a backseat during the game, supporting from the sidelines instead of playing. This usage suggests accepting a less central role, at least temporarily.