noun

atmosphere

A unit of pressure equal to standard air pressure at sea level.

The gauge shows a pressure of two atmospheres inside the chamber.

Etymology

Greek atmos and sphaira describe a sphere of vapor, the gaseous envelope around Earth. The pressure unit takes its name from the standard pressure exerted by that surrounding air.

More examples

  • Standard sea-level pressure is one atmosphere.
  • The experiment compared results at one and three atmospheres.
  • She converted the pressure from atmospheres to pascals.

Forms

atmosphere · atmospheres

Similar words

pascal
Is a much smaller pressure unit defined by force per area.
bar
Is close to one atmosphere but slightly smaller.