noun

• The gases surrounding the Earth or any astronomical body.
• The air in a particular place.
• (figuratively) The conditions (such as music, illumination etc.) that can influence the mood felt in an environment.
• (figuratively) The apparent mood felt in an environment.
• A unit of measurement for pressure equal to 101325 Pa (symbol: atm), approximately the atmospheric pressure at sea level.
• (television, film, uncountable) Extras in a scene who have no spoken lines.