windmill

Etymology

From Middle English wyndmylne, wyndmylle, equivalent to wind + mill. Cognate with Scots wyndmyln, wyndmyl, Saterland Frisian Wíendmäälne, West Frisian wynmûne, Dutch windmolen, Afrikaans windmeul, Dutch Low Saxon windmölle (Achterhooks), wiendmeule (Drents, Veluws), German Low German Windmöhl, German Windmühle, Danish vindmølle, Norwegian Bokmål vindmølle, Norwegian Nynorsk vindmølle, vindmylne, Swedish vindmölla, Icelandic vindmylla.

noun

1. A machine which translates linear motion of wind to rotational motion by means of adjustable vanes called sails.
   Turbines have been around for a long time—windmills and water wheels are early examples. The name comes from the Latin turbo, meaning vortex, and thus the defining property of a turbine is that a fluid or gas turns the blades of a rotor, which is attached to a shaft that can perform useful work. 2013 July-August, Lee S. Langston, “The Adaptable Gas Turbine”, in American Scientist
2. The structure containing such machinery.
3. A child's toy consisting of vanes mounted on a stick that rotate when blown by a person or by the wind.
4. (basketball) A dunk where the dunker swings his arm in a circular motion before throwing the ball through the hoop.
5. (baseball) A pitch where the pitcher swings his arm in a circular motion before throwing the ball.
6. A guitar move where the strumming hand mimics a turning windmill.
7. A breakdancing move in which the dancer rolls his/her torso continuously in a circular path on the floor, across the upper chest, shoulders and back, while twirling the legs in a V shape in the air.
8. Any of various muscle exercises in which a large deal of the body makes a great circle, typically one where a kettlebell is raised overhead and the torso is rotated to the other side with the hand reaching its foot (hitting the core, glutes, hamstrings, trapezius, rhomboids, deltoids and rotator cuffs) but sometimes even a windshield wiper.
9. Any of various large papilionid butterflies of the genus Byasa, the wings of which resemble the vanes of a windmill.
10. (juggling) The false shower.
11. (figurative) An imaginary enemy, but presented as real.

verb

1. (transitive, intransitive) To rotate with a sweeping motion.
   She ran down the hill, windmilling her arms with glee.
   The main thing now was to find the steering wheel. At first, Billy windmilled his arms, hoping to find it by luck. 1969, Kurt Vonnegut, chapter 2, in Slaughterhouse-Five, New York: Dial, published 2005, page 59
   True to her word, her hips windmilled in a frenzy. 1999, Jon Sharpe, Texas Hellion
   As the Pirate Captain strained at the ham, the whale began to spasm and buck about in the water. Its tail thrashed wildly up and down. Its flippers windmilled in the air uselessly. 2005, Gideon Defoe, The Pirates!: in an adventure with Ahab, page 140
2. (intransitive) Of a rotating part of a machine, to (become disengaged and) rotate freely.
   The axle broke and the wheel windmilled in place briefly before careening through the wall.
   When he went to switch on his rotary engine again, the Le Rhone refused to pick up. Nothing happened! The propeller simply windmilled in the slip stream. Garros knew immediately what was wrong and cursed himself for his imbecility. 2000, Walter J. Boyne, Philip Handleman, Brassey's Air Combat Reader, page 18
   The propeller windmilled in front of them. Creede tried to start the engine. It growled like something angry, died away. "We're ... gonna have to ... ride this thing ... to the ground." 2004, Deborah Bedford, If I Had You
   […] the propeller blade on number-four engine windmilled in the air stream. "I wasn't too concerned about it, really," recalls Butchart. "B-29 engines are not all that dependable." 2006, James R. Hansen, First Man: The Life of Neil A. Armstrong, page 134