Blinker (noun)

1. A device on a vehicle for signaling a change in direction, typically consisting of a flashing light.
2. A light that flashes on and off in order to signal a change of direction or to communicate with other drivers.

Origin:

The origin of the word blinker is uncertain, it may have come from the word "blink" meaning a short, sudden closing and opening of the eyes. it is first recorded in english in the 19th century. .

Examples:

1. He turned on the blinker before making the turn.
2. She signaled her turn with the blinker.
3. The blinker on the car wasn't working.
4. The blinker on the bike was flashing red.
5. He used the blinker to indicate that he was changing lanes.