blinker

noun

1.
a light that flashes on and off; used as a signal or to send messages
Derived from:
blink
2.
a blinking light on a motor vehicle that indicates the direction in which the vehicle is about to turn
Derived from:
blink
3.
blind consisting of a leather eyepatch sewn to the side of the halter that prevents a horse from seeing something on either side
Derived from:
blinker