The word "windmill" has its origins in the Old English words "wind" and "myln", meaning "wind" and "mill", respectively. The term "windmill" first appeared in the English language in the 14th century, and it was used to describe a mill that was powered by the wind. Windmills have been used for centuries to grind grain, pump water, and generate electricity. Today, windmills are still used in many parts of the world, and they are an important source of renewable energy.