noun
anemoscope
A meteorological instrument that shows the direction of the wind, distinct from an anemometer which measures wind speed. Technical term.
風向計は風の方向を観測するのに使われる。
An anemoscope is used to observe wind direction.
風見 is a more common, everyday term for a weather vane or wind indicator, whereas 風向計 is a technical instrument.
Compound of 風向 (wind direction) and 計 (meter, gauge).