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.
With mounting social, economic, and immigration pressures on Latinas, combined with care cuts, these maternal mortality rates are likely to rise. Noreen Sugrue, Forbes.com, 31 Aug. 2025 If the problem goes untreated among cattle, the mortality rate of the infestation can be high, Scott said. N'dea Yancey-Bragg, USA Today, 28 Aug. 2025 Studies conducted in the region surrounding the Semipalatinsk test site found that cancer mortality rates and infant mortality rates during the most intensive period of nuclear testing, from 1949 to 1962, were higher than elsewhere in Kazakhstan. Issy Ronald, CNN Money, 24 Aug. 2025 Building upon this study, the ACES Act requires the secretary of veterans affairs to investigate cancer and mortality rates for aircrew members who have served in the Navy, Air Force and Marine Corps. Center Square, The Washington Examiner, 23 Aug. 2025 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 9 Sep. 2025.

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
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