Treadmill/ˈtredmɪl/ Definition 1 of 2Pro Tip 1/3Physical Fitness The word 'treadmill' often relates to exercise, health, and gym culture. Joining a gym, I spend half an hour on the treadmill to stay fit. Pro Tip 2/3Stay Stationary 'Treadmill' implies movement without changing location, useful for indoor workouts. It's raining outside, so I'll use the treadmill for my daily run. Pro Tip 3/3Modern Convenience A 'treadmill' represents technology that enables exercise at home or in a gym. With a treadmill at home, there's no excuse to skip a workout.