"Today, the Term Dry Run Is Often Used to Refer

"Today, the term dry run is often used to refer to a rehearsal of some sort. This meaning originated in the field of firefighting, where dry represented a practice drill where the hoses were turned off, and run simply meant a response to a fire alarm, whether real or for a drill." What type of definition is given in this statement?

A) operational definition
B) definition by example
C) definition by synonym
D) definition by etymology