IPA: /ˈætməsfɪə/
KK: /ˈætməsˌfɪr/
The layer of gases surrounding the Earth or another planet, or the general mood or feeling in a particular place or situation.
The atmosphere in the restaurant was warm and inviting, making it a perfect place for a date.
Atmosphere is formed from "atmo-" (from Greek "atmos", meaning vapor or steam) and "sphaira" (meaning sphere). The word describes the vaporous layer or sphere surrounding the Earth.
Imagine a 'vapor' ('atmo-') surrounding the Earth like a 'sphere' ('sphaira') — that's what atmosphere means.