flywheel

noun

fly·​wheel ˈflī-ˌ(h)wēl 

: a heavy wheel for opposing and moderating by its inertia any fluctuation of speed in the machinery with which it revolves

also : a similar wheel used for storing kinetic energy (as for motive power)

Did you know?

A heavy wheel attached to a rotating shaft, a flywheel smooths out delivery of power from a motor to a machine. The inertia of the flywheel moderates fluctuations in the speed of the engine and stores the excess energy for intermittent use. In automobile engines, the flywheel smooths out the pulses of energy provided by combustion in the cylinders, and provides energy for the compression stroke of the pistons. In power presses, the punching, shearing, and forming are done in a fraction of the operating cycle. During the rest of the cycle, the speed of the flywheel is built up by a comparatively low-powered motor, and most of the required energy for the cycle is provided by the flywheel.

Examples of flywheel in a Sentence

Recent Examples on the Web

Moreover, big firms enjoy powerful flywheel effects. —Ilona Limonta-Volkova, Forbes.com, 18 May 2025

That one dinner turned into a spectacular friendship and a flywheel of professional opportunity. —Chris Schembra, Rolling Stone, 29 Apr. 2025

By and large, the flywheel effect is considered to be a good thing. —Trevor Clawson, Forbes.com, 25 Apr. 2025

That openness, paired with UT’s legacy of breakthroughs fuels a flywheel of innovation unlike anywhere else. —Amir Husain, Forbes, 22 Mar. 2025

Word History

First Known Use

1784, in the meaning defined above

Rhymes for flywheel

• abele
• alkyl
• anneal
• appeal
• cartwheel
• conceal
• congeal
• coquille
• corneal
• cornmeal
• foveal
• genteel

Kids Definition

flywheel

noun

fly·​wheel -ˌhwēl  -ˌwēl 

: a heavy wheel for regulating the speed of machinery