/bəˈrämitər/
Noun, pl. barometers
1. An instrument measuring atmospheric pressure, used esp. in forecasting the weather and determining altitude. (Google Dictionary)
2. A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. (wikipedia.org)
3. Anything used as a gauge or indicator. (wiktionary.org)
Word origin: From Ancient Greek βάρος (“weight”) + –meter.