bar

A unit of pressure equal to one million baryes, also called a megabarye for that reason. Atmospheric pressure is usually expressed in hectopascals (hPa), so that 1 bar = 1000 hPa (pascal and hectopascal). Like other meteorological terms related to pressure, such as barometer, baroclinic, or baric, 'bar' has its etymological origin in the Greek term báros, which means weight. The greater the weight of a column of air, the greater the pressure it exerts, and vice versa.