The word "weatherglass" is an old term that refers to a type of barometer used to measure changes in atmospheric pressure, which are indicative of changes in the weather. It is related to words such as weather vane and weathercock which are also weather instruments. There are several synonyms for the term "weatherglass" including barometer, aneroid barometer, weather indicator, atmospheric gauge, and pressure sensor. These words are useful when talking about weather forecasting or climate science studies. Whatever synonym is used, knowing how to interpret the data is essential when it comes to understanding the weather patterns and keeping oneself and others safe.