noun
sudden death; unexpected death
Medical and general term for death that occurs suddenly and unexpectedly, often from natural causes like heart attack or stroke. Also used in non-medical contexts for any abrupt, unforeseen death.
彼は突然死で亡くなった。
He died of sudden death.
突然死の原因を調べるために解剖
An autopsy was performed to investigate the cause of the sudden death.