say it: AT-muh-sfir
atmosphere is a noun meaning "a particular environment or surrounding influence". It carries 6 recorded senses.
a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade
the weather or climate at some place
“the atmosphere was thick with fog”
the envelope of gases surrounding any celestial body
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for atmosphere come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.