Origin: Greek suffix -graph
Chronograph has 3 different meanings across 1 category:
an accurate timer for recording time
"The diver pressed the button on his chronograph to start the race, ensuring every second of performance was accurately recorded."
A chronogram.
"The historian pointed out that the inscription on the ancient pillar was a clever chronogram, encoding the exact year of its construction within the letters themselves."
To make an accurate measurement of the speed of a projectile.
"The engineer fired the chronograph to measure exactly how fast the bullet was traveling downrange."