Barometer

n. instrument for measuring atmospheric pressure and weather changes

A barometer is an instrument used to measure atmospheric pressure. It can measure the pressure exerted by the atmosphere by using water, air, or mercury. Pressure tendency can forecast short term changes in the weather. Numerous measurements of air pressure are used within surface weather analysis to help find surface troughs, high pressure systems, and frontal boundaries.
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Noun
1. an instrument that measures atmospheric pressure
(hypernym) measuring instrument, measuring system, measuring device
(hyponym) aneroid barometer, aneroid

n. barometer, instrument for measuring atmospheric pressure and weather changes; weatherglass, instrument for measuring atmospheric pressure or other atmospheric conditions

n. barometer, weatherglass, instrument for measuring atmospheric pressure and weather changes (Meteorology)