• noun:   the mass of air surrounding the Earth

  Example: "There was great heat as the comet entered the atmosphere"

• noun:   the envelope of gases surrounding any celestial body
• noun:   the weather or climate at some place

  Example: "The atmosphere was thick with fog"

• noun:   a particular environment or surrounding influence

  Example: "There was an atmosphere of excitement"

• noun:   a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade
• noun:   a distinctive but intangible quality surrounding a person or thing

  Example: "An atmosphere of defeat pervaded the candidate's headquarters"

Related words...