A weather vane is a device used to indicate which direction the wind is blowing in. It typically consists of a flat or curved plate, which rotates on a vertical spindle in response to air currents. There are many synonyms for weather vane, including wind vane, wind sock, anemometer, and weathercock. The term anemometer refers to any instrument used to measure wind speed, while a wind sock is typically a larger, more elaborate device that is used to track wind patterns over longer periods of time. Weathercocks, on the other hand, are traditional weathervanes in the form of a rooster or other bird that point in the direction of the wind.