from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A heavy-rimmed rotating wheel used to minimize variations in angular velocity and revolutions per minute, as in a machine subject to fluctuation in drive and load.
- n. An analogous device, especially one used to regulate the speed of clockwork.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a rotating mass used to maintain the speed of a machine within certain limits while the machine receives or releases energy at a varying rate
from the GNU version of the Collaborative International Dictionary of English
- n. a heavy wheel attached to machinery to equalize the movement (opposing any sudden acceleration by its inertia and any retardation by its momentum), and to accumulate or give out energy for a variable or intermitting resistance. See Fly, n., 9.
- n. A heavy wheel or disk which stores kinetic energy by rotating on a shaft, and by its momentum smoothes the operation of a reciprocating engine by reducing fluctuations of speed. It is used in certain types of machinery, such as automobiles.
from The Century Dictionary and Cyclopedia
- n. In machinery, a wheel with a heavy rim placed on the revolving shaft of any machinery put in motion by an irregular or intermitting force or meeting with an irregular or intermittent resistance, for the purpose of rendering the motion equable and regular by means of its momentum.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. regulator consisting of a heavy wheel that stores kinetic energy and smooths the operation of a reciprocating engine
fly + wheel (Wiktionary)