n.1 a the envelope of gases surrounding the earth, any other planet, or any substance. b the air in any particular place, esp. if unpleasant.
2 a the pervading tone or mood of a place or situation, esp. with reference to the feelings or emotions evoked. b the feelings or emotions evoked by a work of art, a piece of music, etc.
3 Physics a unit of pressure equal to mean atmospheric pressure at sea level, 101,325 pascals.
Usage:
Abbr.: atm.
Derivatives:
atmospheric adj. atmospherical adj. atmospherically adv.
Etymology: mod.L atmosphaera f. Gk atmos vapour: see SPHERE