Atmosphere

n. layer of gases surrounding the earth; layer of gases surrounding a planet; climate of a particular region; unit of air pressure (Physics); tone or mood of a place or thing

An atmosphere is a layer of gases that may surround a material body of sufficient mass. The gases are attracted by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, and thus have very deep atmospheres (see gas giants).
See more at Wikipedia.org...

Atmosphere /at·mos·phere/ 1. the entire gaseous envelope surrounding the earth and subject to the earth's gravitational field. 2. [more]Atmosphere - Community and Resources

Noun
1. a particular environment or surrounding influence; "there was an atmosphere of excitement"
(synonym) ambiance, ambience
(hypernym) condition, status
(hyponym) genius loci
2. a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade
(synonym) standard atmosphere, atm, standard pressure
(hypernym) pressure unit
(hyponym) STP, s.t.p.
3. the mass of air surrounding the Earth; "there was great heat as the comet entered the atmosphere"; "it was exposed to the air"
(synonym) air
(hypernym) region, part
(hyponym) airspace
(part-holonym) Earth, world, globe
(part-meronym) airspace, air space
4. the weather or climate at some place; "the atmosphere was thick with fog"
(synonym) atmospheric state
(hypernym) weather, weather condition, atmospheric condition
(hyponym) air mass
5. the envelope of gases surrounding any celestial body
(hypernym) gas
(part-meronym) exosphere
6. 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"
(synonym) air, aura
(hypernym) quality
(hyponym) mystique

n. atmosphere, ambience; feeling, go; vibes, aura