traffic light

noun

1. A signalling device positioned at a road intersection or pedestrian crossing indicating the moment it is safe to drive, ride or walk, using a universal color code.

   “In Sydney you'd better be riding the clutch and completely in sync with the traffic lights so that your car is already moving as they turn green.”

2. A signalling device positioned at a road intersection or pedestrian crossing indicating the moment it is safe to drive, ride or walk, using a universal color code.

   “How do I get to the hospital? ~ You go straight on to the traffic lights, then turn left at the traffic lights and the hospital is on your right.”

3. A colour code using the three signals of a traffic light (green, yellow or amber, and red) as a metaphor.

   “The Department of Health recommends that food packaging display the recommended daily intake with a traffic light system, for ease of understanding.”

4. The colored dots on stamp sheet margins printed with offset printing or photogravure methods, used by the printers to check color accuracy.
5. In Conway's Game of Life, an arrangement of four blinkers that are orthogonally equidistant from a central point.