a mill that is powered by the wind
"The old windmill at the edge of the field began to spin as the afternoon breeze picked up."
generator that extracts usable energy from winds
"The new windmill on the hill will start generating electricity for our neighborhood once the gale picks up."
A machine which translates linear motion of wind to rotational motion by means of adjustable vanes called sails.
"The ancient windmill used its large, adjustable sails to catch the breeze and grind grain into flour for the village bakery."
To rotate with a sweeping motion.
"The giant fan blades on the ceiling windmill rotated with a gentle, sweeping motion to cool the room."