treadmill

American  

[tred-mil] / ˈtrɛdˌmɪl /

noun

1. an apparatus for producing rotary motion by the weight of people or animals, treading on a succession of moving steps or a belt that forms a kind of continuous path, as around the periphery of a pair of horizontal cylinders.

2. an exercise machine that allows the user to walk or run in place, usually on a continuous moving belt.

3. any monotonous, wearisome routine in which there is little or no satisfactory progress.

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treadmill British  

/ ˈtrɛdˌmɪl /

noun

1. Also called: treadwheel.  (formerly) an apparatus used to produce rotation, in which the weight of men or animals climbing steps on or around the periphery of a cylinder or wheel caused it to turn

2. a dreary round or routine

3. an exercise machine that consists of a continuous moving belt on which to walk or jog

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Etymology

Origin of treadmill

First recorded in 1815–25; tread + mill ¹

Explanation

A treadmill is an exercise machine for walking or running in place. If it's bitterly cold outside, you might decide to go to the gym and run on the treadmill instead of taking your usual outdoor jog. A treadmill was originally a type of human- or animal-powered machine. By walking on a wheel fitted with steps, a person (or animal) turned it, grinding grain in the process. Treadmills were also used as punishment in prisons where inmates were forced to work. Today the only treadmills you're likely to see are in a gym, but the word is commonly used in a figurative way for any relentless, boring job.

Example Sentences

Still, performing is clearly on his mind as he leads me into a tile-roofed gym equipped with weights, a treadmill and a massage table.

From Los Angeles Times • May 27, 2026

During these sessions, participants walked on a treadmill while wearing a device on the shin that provided vibration feedback.

From Science Daily • May 22, 2026

“They already have the standing desks, the treadmill walks, but the scans and assessments help them realize they need to strengthen their lower body,” Thompson says.

From The Wall Street Journal • May 16, 2026

"We just need to also think about the bigger picture to stop more people heading on to this treadmill of obesity later in life."

From BBC • May 16, 2026

Once I finished with my weight training, I stepped onto my treadmill.

From "Ready Player One: A Novel" by Ernest Cline