‘死亡率’ literally combines ‘死’ (to die), ‘亡’ (to perish, often used in formal or literary contexts), and ‘率’ (rate or ratio). Together, it means ‘mortality rate’ — the proportion of deaths within a defined population over a specific time period, usually expressed per 1,000 or 100,000 people. It is a key public health and epidemiological metric used to assess disease severity, healthcare quality, or demographic trends.

This term appears frequently in medical reports, news articles about outbreaks or aging populations, and academic research. Unlike casual terms like ‘死亡人数’ (number of deaths), ‘死亡率’ emphasizes proportionality — it accounts for population size, making comparisons across regions or time periods meaningful. It’s always followed by a time frame (e.g., ‘每年’, ‘2023年’) and often specifies the population (e.g., ‘婴儿死亡率’, ‘老年人死亡率’).