Speed

noun

1. The state of moving quickly or the capacity for rapid motion; rapidity.

   "How does Usain Bolt run at that speed?"

2. The rate of motion or action, specifically / the magnitude of the velocity; the rate distance is traversed in a given time.

   "Speed limits provide information to the drivers about the safe speed to travel in average conditions."

3. The sensitivity to light of film, plates or sensor.
4. The duration of exposure, the time during which a camera shutter is open (shutter speed).
5. The largest size of the lens opening at which a lens can be used.