(historical) A mill worked by persons treading upon steps on the periphery of a wide wheel having a horizontal axis. It was used principally as a means of prison discipline.

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Details

Sense（3）

A mill worked by horses, dogs, etc., treading an endless belt.

Ancient nomads, wishing to ward off the evening chill and enjoy a meal around a campfire, had to collect wood and then spend time and effort coaxing the heat of friction out from between sticks to kindle a flame. With more settled people, animals were harnessed to capstans or caged in treadmills to turn grist into meal.

Google Translation / DeepL Translation