1. moved in a circular motion like the arms or blades of a windmill

Examples

• The pitcher windmilled his arm to warm up before the game.
• She windmilled her arms wildly as she lost her balance on the ice.
• The swimmer windmilled through the water with powerful strokes.
• He windmilled his arms to get the crowd’s attention.
• The dancer windmilled gracefully across the stage.
• The child windmilled her arms excitedly when she saw the parade.