Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
atrial is an adjective meaning "of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart)". It carries one recorded sense.
of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart)
anatomy
Definitions, synonyms and semantic relations for atrial come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.