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

The transformational flywheel can address all three by focusing on satisfaction and retention of the end user. —Venkatesh Jayaraman, Forbes.com, 11 June 2025

Better client relationships also means Preqin can create a flywheel effect within BlackRock. —Morgan Chittum, CNBC, 10 June 2025

The flywheel technology makes the rides seem natural. —Bestreviews, Chicago Tribune, 17 Apr. 2025

Musk is used to being leveraged, trading on his reputation or his illiquid assets to keep the flywheel spinning. —Charlie Warzel, The Atlantic, 12 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