Read the dictionary definition of blinker. All definitions for this word.
1. a light that flashes on and off; used as a signal or to send messages
2. blind consisting of a leather eyepatch sewn to the side of the halter that prevents a horse from seeing something on either side
3. a blinking light on a motor vehicle that indicates the direction in which the vehicle is about to turn
4. put blinders on (a horse)