mortality rate

noun

plural mortality rates
: the ratio between deaths and individuals in a specified population and during a particular time period : the incidence of deaths in a given population during a defined time period (such as one year) that is typically expressed per 1000 or 100,000 individuals : death rate
an annual mortality rate of 15 deaths per 1000 people

Note: A crude mortality rate does not distinguish between specific causes of death or groups of individuals and measures the incidence of all deaths in a population during a given time period. More specific mortality rates are based on narrower categories of individuals or causes of death.

an infant mortality rate of 9 deaths per 1000 live births
mortality rates of lung cancer patients
infectious disease mortality rates

Examples of mortality rate in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Maternal mortality rates in the United States have dropped to their lowest levels in recent years, according to new data published on Thursday. Mary Kekatos, ABC News, 4 Mar. 2026 For women living in sub-Saharan Africa, which includes some of the highest mortality rates worldwide, the numbers are especially alarming. Asuka Koda, CNN Money, 2 Mar. 2026 Their infants face mortality rates more than double the national average. Nicky Zizaza, CBS News, 26 Feb. 2026 According to American Cancer Society findings, African Americans continue to face the highest colorectal cancer burden, with a 20% higher incidence and 40% higher mortality rate than most other groups. Ernesto Fonts, Sun Sentinel, 24 Feb. 2026 See All Example Sentences for mortality rate

Word History

First Known Use

1855, in the meaning defined above

Time Traveler
The first known use of mortality rate was in 1855

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Cite this Entry

“Mortality rate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mortality%20rate. Accessed 10 Mar. 2026.

Medical Definition

mortality rate

noun
: the ratio between deaths and individuals in a specified population and during a particular time period : the incidence of deaths in a given population during a defined time period (such as one year) that is typically expressed per 1000 or 100,000 individuals : death rate
an annual mortality rate of 15 deaths per 1000 people

Note: A crude mortality rate does not distinguish between specific causes of death or groups of individuals and measures the incidence of all deaths in a population during a given time period. More specific mortality rates are based on narrower categories of individuals or causes of death.

mortality rates of liver cancer patients
an infant mortality rate of 9 deaths per 1000 live births
Last Updated: - Updated example sentences
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