Running time refers to the duration of a particular event or activity. There are many synonyms that can be used in place of running time, such as duration, length, time frame, period of time, time span, and time elapsed. These words can be used interchangeably to describe the amount of time that a particular event or activity takes to complete. Other synonyms for running time include timing, pace, speed, and rate of progress. These words can be used to describe the speed or pace at which something is progressing, or the rate at which it is being completed. Overall, there are many synonyms available to describe the concept of running time in a variety of ways.