What is the meaning of atmosphere?

noun

• A particular environment or surrounding influence.
  • usage: "there was an atmosphere of excitement"
  • synonyms: ambiance, ambience
• A unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade.
  • synonyms: standard atmosphere, atm, standard pressure
• The mass of air surrounding the Earth.
  • usage: "there was great heat as the comet entered the atmosphere"; "it was exposed to the air"
  • synonyms: air
• The weather or climate at some place.
  • usage: "the atmosphere was thick with fog"
  • synonyms: atmospheric state
• The envelope of gases surrounding any celestial body.
• A distinctive but intangible quality surrounding a person or thing.
  • usage: "an air of mystery"; "the house had a neglected air"; "an atmosphere of defeat pervaded the candidate's headquarters"; "the place had an aura of romance"
  • synonyms: air, aura