treadmill

noun

tread·​mill ˈtred-ˌmil 

1

a

: a device having an endless belt on which an individual walks or runs in place for exercise or physiological testing

b

: a mill worked by an animal treading an endless belt

c

: a mill worked by persons treading on steps on the periphery of a wide wheel having a horizontal axis and used formerly in prison punishment

2

: a wearisome or monotonous routine resembling continued activity on a treadmill

the office treadmill

Synonyms

• routine
• grind

Examples of treadmill in a Sentence

the treadmill of exhausting family schedules

the treadmill of the morning commute to work

Recent Examples on the Web

Afterward, retreat to the spa’s relaxation lounge—where a glowing copper teardrop floats above cedar banquettes—while next door, the subterranean fitness center boasts Technogym gear and treadmills—all below the waterline. —Lewis Nunn, Forbes.com, 6 Sep. 2025

Early buzz for the adaptation is strong, and the online reaction to the treadmill activation has been quietly extraordinary to watch. —Alison Foreman, IndieWire, 4 Sep. 2025

Walking trends have exploded across social media, from the 12-3-30 treadmill challenge to the rise of Zone 2 training. —Khloe Quill, FOXNews.com, 24 Aug. 2025

After pushing his group to finish a treadmill run, Harper berated Gwynn for slowing down in the final seconds. —Emily Blackwood, People.com, 23 Aug. 2025

Word History

First Known Use

1822, in the meaning defined at sense 1c

Rhymes for treadmill

• anthill
• backfill
• bluegill
• crossbill
• distil
• distill
• downhill
• dunghill
• foothill
• fulfil
• fulfill
• goodwill

Kids Definition

treadmill

noun

tread·​mill ˈtred-ˌmil 

1

a

: a device moved by persons treading on steps set around the rim of a wide wheel or by animals walking on an endless belt

b

: a device having an endless belt on which an individual walks or runs in place for exercise or medical testing

2

: a tiring or monotonous routine

Medical Definition

treadmill

noun

tread·​mill ˈtred-ˌmil 

: a device having an endless belt on which an individual walks or runs in place that is used for exercise and in tests of physiological functions see stress test