indicator

/ˈɪndɪkeɪtər/
noun
  1. A sign or signal that shows the condition or existence of something.
    • Rising prices are a strong indicator of inflation in the economy.
    • A fever is often an indicator of an infection.
    • Her smile was a good indicator that she enjoyed the surprise.
  2. A device that shows information, such as a light, gauge, or needle on a dashboard or panel.
    • He checked the temperature indicator on the oven before putting in the cake.
    • The speed indicator on the dashboard stopped working during the trip.
    • The fuel indicator showed that the tank was almost empty.
  3. A turn signal on a vehicle.
    • She flicked on her left indicator and pulled into the parking lot.
    • The car's indicator was blinking, but the driver didn't turn.
    • Don't forget to use your indicator before changing lanes.