1. A mill that is powered by the wind
   "The old windmill stood tall on the hill, its blades turning slowly in the breeze"
    
2. Generator that extracts usable energy from winds
   "The wind farm used windmills to produce clean electricity";
   - aerogenerator, wind generator
    
3. [Brit] A toy windmill consisting of vanes of coloured paper or plastic attached to a stick that spins when exposed to wind
   "Children ran across the beach with colourful windmills spinning in their hands";
   - pinwheel [N. Amer], pinwheel wind collector [N. Amer]

1. Rotate one's arms with a sweeping motion
   "she ran down the hill, windmilling her arms with glee"
    
2. (of a rotating part of a machine) become disengaged and rotate freely
   "The axle broke and the wheel windmilled in place"

Derived forms: windmilled, windmilling, windmills

Type of: generator, grinder, mill, milling machinery, plaything, toy

Encyclopedia: Windmill, Derbyshire