blinker

Anything that blinks.

She was a frequent blinker, always on the verge of tears.

The turn signal of an automobile.

A shield attached to the bridle of a horse or other domesticated animal to prevent it from seeing things behind it and to its side.

Whatever obstructs sight or discernment.

This floor let not the vulgar tread, / Who worship only what they dread: / Nor bigots who but one way see, / Through blinkers of authority

The eyelid.

To put blinkers on.

The farmer stopped to blinker his horse before riding into an area of heavy traffic.