|1.||an instrument for measuring atmospheric pressure, usually to determine altitude or weather changes|
|2.||anything that shows change or impending change: the barometer of social change|
|air pollution containing ozone and reactive chemical compounds formed by sunlight on nitrogen oxides and hydrocarbons, often from auto exhaust|
|a bright, sunny, cloudless to half-cloudy sky, with no prospect of rain, snow, or hail; not stormy|
|barometer (bə-rŏm'ĭ-tər) Pronunciation Key
An instrument for measuring atmospheric pressure. Barometers are used in determining height above sea level and in forecasting the weather. The two primary types of barometers are the aneroid and the mercury barometer.