A blinker is a flashing light on a vehicle that signals which direction the driver plans to turn. When you're riding in a car and see the left blinker flashing, it means the driver is about to turn left or change lanes to the left. The rhythmic clicking sound and the flashing amber light warn other drivers and pedestrians about what's coming next.

Using your blinker is both a legal requirement and a courtesy. It gives everyone around you time to react safely. A driver who forgets to use their blinker (or refuses to) creates confusion and danger, since other people can't predict what the vehicle will do next.

The word can also describe something that blocks your view or limits your perspective. Blinders (also called blinkers) are leather flaps that horses wear beside their eyes to help them focus straight ahead and prevent them from getting spooked by movement on the sides. When someone has blinders on or is blinkered, they're so focused on one thing that they miss other important information. A student with blinders on might study one chapter so intensely that they forget the test covers three chapters.