flywheel

American  

[flahy-hweel, -weel] / ˈflaɪˌʰwil, -ˌwil /

noun

Machinery.

1. a heavy disk or wheel rotating on a shaft so that its momentum gives almost uniform rotational speed to the shaft and to all connected machinery.

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flywheel British  

/ ˈflaɪˌwiːl /

noun

1. a heavy wheel that stores kinetic energy and smooths the operation of a reciprocating engine by maintaining a constant speed of rotation over the whole cycle

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Etymology

Origin of flywheel

First recorded in 1775–85; fly ² + wheel

Example Sentences

They use a "flywheel exercise device," similar to a yo-yo, that can allow for aerobics like rowing as well as provide resistance to perform moves like weighted squats and deadlifts.

From Barron's • Apr. 4, 2026

"The more capital we can free up within the organisation to invest, the better we can turn this flywheel of making investments to drive future growth," chief financial officer Anat Ashkenazi said.

From BBC • Mar. 29, 2026

“But it lacks a large-scale authenticated consumer network, consumer brand and the data flywheel that a two-sided network could provide.”

From MarketWatch • Feb. 24, 2026

As the structure moves with the waves, the rotating flywheel converts that motion into electrical power.

From Science Daily • Feb. 18, 2026

The starter cord was a three-foot length of rope that wrapped tightly around the engine’s flywheel.

From "Flush" by Carl Hiaasen