Definition of "Atmosphere" :

noun: a distinctive but intangible quality surrounding a person or thing

"An atmosphere of defeat pervaded the candidate's headquarters."

noun: the mass of air surrounding the Earth

"There was great heat as the comet entered the atmosphere."

noun: the envelope of gases surrounding any celestial body

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: the weather or climate at some place

"The atmosphere was thick with fog."

noun: a particular environment or surrounding influence

"There was an atmosphere of excitement."