Atmosphere (noun)

1. The layer of gases surrounding a planet or celestial body.
2. The feeling or mood surrounding a particular place, person, or situation.
3. The air pressure at a particular location.

Origin:

Derived from the greek word "atmos" meaning vapor and "sphaira" meaning sphere, the word "atmosphere" was first used in the 17th century to describe the layer of gases surrounding the earth.

Examples:

1. The atmosphere of Mars is primarily composed of carbon dioxide.
2. The atmosphere at the party was festive and lively.
3. The atmosphere in the room was tense as the witnesses testified.
4. The atmosphere in the city was suffocating due to the high pollution levels.
5. The atmosphere in the forest was peaceful and serene.