say it: AY-tree-uhm
atrium is a noun meaning "any chamber that is connected to other chambers or passageways (especially one of the two upper chambers of the heart)". It carries 2 recorded senses.
any chamber that is connected to other chambers or passageways (especially one of the two upper chambers of the heart)
the central area in a building; open to the sky
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 atrium 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.