1. a watch with a hand or display that can be started and stopped to time events

Examples

• The coach used a stopwatch to time the runners.
• She clicked the stopwatch as the race began.
• The scientist recorded the reaction time with a digital stopwatch.
• He forgot to stop the stopwatch after the experiment ended.
• The stopwatch showed that the swimmer had beaten her personal record.
• Press the button to start the stopwatch.