[ wind-mil ]
See synonyms for windmill on
  1. any of various machines for grinding, pumping, etc., driven by the force of the wind acting upon a number of vanes or sails.

  2. (loosely) a wind generator; wind plant.

  1. Aeronautics. a small air turbine with blades, like those of an airplane propeller, exposed on a moving aircraft and driven by the air, used to operate gasoline pumps, radio apparatus, etc.

  2. an imaginary opponent, wrong, etc. (in allusion to Cervantes' Don Quixote): to tilt at windmills.

verb (used with or without object)
  1. Aeronautics. (of a propeller engine or turbojet engine) to rotate or cause to rotate solely under the force of a passing airstream.

Origin of windmill

Middle English word dating back to 1250–1300; see origin at wind1, mill1

Words Nearby windmill Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use windmill in a sentence

British Dictionary definitions for windmill


/ (ˈwɪndˌmɪl, ˈwɪnˌmɪl) /

  1. a machine for grinding or pumping driven by a set of adjustable vanes or sails that are caused to turn by the force of the wind

  2. the set of vanes or sails that drives such a mill

  1. Also called: whirligig British a toy consisting of plastic or paper vanes attached to a stick in such a manner that they revolve like the sails of a windmill: US and Canadian name: pinwheel

  2. an imaginary opponent or evil (esp in the phrase tilt at or fight windmills)

  3. a small air-driven propeller fitted to a light aircraft to drive auxiliary equipment: Compare ram-air turbine

  4. an informal name for helicopter

  5. an informal name for propeller (def. 1)

  1. to move or cause to move like the arms of a windmill

  2. an informal name for accommodation bill

  1. (intr) (of an aircraft propeller, rotor of a turbine, etc) to rotate as a result of the force of a current of air rather than under power

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with windmill


see tilt at windmills.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.