A mill operated by the power of the wind, usually by the action of the wind upon oblique vanes or sails which radiate from a horizontal shaft. Chaucer. [1913 Webster]

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OXFORD DICTIONARY

windmill, n.
1 a mill worked by the action of the wind on its sails.
2 esp. Brit. a toy consisting of a stick with curved vanes attached that revolve in a wind.

Idiom

throw one's cap (or bonnet) over the windmill act recklessly or unconventionally. tilt at (or fight) windmills attack an imaginary enemy or grievance.

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ROGET THESAURUS

windmill

Rotation

N rotation, revolution, spinning, gyration, turning about an axis, turning aound an axis, circulation, roll, circumrotation, circumvolution, circumgyration, volutation, circination, turbination, pirouette, convolution, verticity, whir, whirl, eddy, vortex, whirlpool, gurge, countercurrent, Maelstrom, Charybdis, Ixion, cyclone, tornado, whirlwind, dust devil, spin-out, axis, axis of rotation, swivel, pivot, pivot point, axle, spindle, pin, hinge, pole, arbor, bobbin, mandrel, axle shaft, gymbal, hub, hub of rotation, helix, helical motion, angular momentum, angular velocity, revolutions per minute, RPM, centrifugal force, surge, vertigo, dizzy round, coriolus force, carousel, merry-go-round, Ferris wheel, top, dreidel, teetotum, gyroscope, turntable, lazy suzan, screw, whirligig, rollingstone, water wheel, windmill, wheel, pulley wheel, roulette wheel, potter's wheel, pinwheel, gear, roller, flywheel, jack, caster, centrifuge, ultracentrifuge, bench centrifuge, refrigerated centrifuge, gas centrifuge, microfuge, drill, augur, oil rig, wagon wheel, wheel, tire, tyre, trochilics, whirling dervish, rotating, rotary, rotary, circumrotatory, trochilic, vertiginous, gyratory, vortical, vorticose, head over heels, round and round, like a horse in a mill.

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