trafficator

/T R AE1 F IH0 K EY0 T ER0/
noun
  1. 1

    A blinking light on a motor vehicle that indicates the direction in which it is about to turn.

  2. 2

    A semaphore device with a steady light that served the same purpose on early vehicles.

Source: https://en.wiktionary.org/wiki/trafficator