The noun atmosphere has 6 senses (first 5 from tagged texts)
1. (18) atmosphere, ambiance, ambience -- (a particular environment or surrounding influence; "there was an atmosphere of excitement")
2. (10) standard atmosphere, atmosphere, atm, standard pressure -- (a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade)
3. (9) atmosphere, air -- (the mass of air surrounding the Earth; "there was great heat as the comet entered the atmosphere"; "it was exposed to the air")
4. (6) atmosphere, atmospheric state -- (the weather or climate at some place; "the atmosphere was thick with fog")
5. (4) atmosphere -- (the envelope of gases surrounding any celestial body)
6. air, aura, atmosphere -- (a distinctive but intangible quality surrounding a person or thing; "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")