1. a tall structure with large blades that turn in the wind to generate power or pump water
2. a building containing machinery for grinding grain, powered by wind

1. to move one’s arms in large circular motions
Usage: informal

Examples

• The old windmill on the hill has been grinding grain for over a century.
• Modern windmills generate clean electricity from wind power.
• Don Quixote famously fought against windmills in the Spanish novel.
• The Dutch countryside is dotted with traditional windmills.
• She windmilled her arms to keep her balance on the narrow beam.
• The wind farm contains dozens of giant windmills.
• The pitcher windmilled his arm before throwing the ball.