atmosphere

Etymology

From French atmosphère, from New Latin atmosphaera, from Ancient Greek ἀτμός (atmós, “steam”) + σφαῖρα (sphaîra, “sphere”); corresponding to atmo- + -sphere.

noun

1. The gases surrounding the Earth or any astronomical body.
   Meronyms: see Thesaurus:atmosphere
2. The air in a particular place.
3. (figurative) The conditions (such as music, illumination etc.) that can influence the mood felt in an environment.
4. (figurative) The apparent mood felt in an environment.
5. A unit of measurement for pressure equal to 101325 Pa (symbol: atm), approximately the atmospheric pressure at sea level.
6. (television, film, uncountable) Extras in a scene who have no spoken lines.
   Central Casting is in the business of extras, also known as atmosphere or background actors […] 2006, Los Angeles Magazine, volume 51, number 2, page 100
   "It is estimated conservatively that there are some 50,000 would-be film extras in and around the celluloid capital, persons who would jump at the opportunity to appear as atmosphere in pictures," Scott concluded. 2013, Kerry Segrave, Extras of Early Hollywood: A History of the Crowd, 1913-1945, page 38
   By the way, I discovered that we were not extras but background, as far as the director was concerned; and for the producer, we were atmosphere. 2015, William R. Phillippe, The Pastor's Diary