mor·​tal·​i·​ty | \mȯr-ˈta-lə-tē \

Definition of mortality 

1 : the quality or state of being mortal Her husband's death reminded her of her own mortality.

2 : the death of large numbers (as of people or animals) trying to reduce infant mortality

3 archaic : death

4 : the human race that natural extinction to which all mortality is subject— Thomas Paine

5a : the number of deaths in a given time or place The mortality among the infected mounted daily.

b : the proportion of deaths to population a brain infection with a mortality rate of about 30 percent— Jane E. Brody

c : the number lost or the rate of loss or failure the mortality rate of small businesses

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Thoughts on Mortality

Young people tend to assume they will never die, but a person's sense of his or her mortality generally increases year by year, and often increases greatly after a serious accident or illness. Still, many people refuse to change behaviors that would improve their chances of living into old age. Mortality rates are calculated by government agencies, insurance companies, and medical researchers. Infant mortality rates (the rate at which infants die in childbirth) provide a good indicator of a country's overall health; in recent years, the rates in countries like Iceland, Singapore, and Japan have been much better than in the U.S.

Examples of mortality in a Sentence

a leading cause of mortality

Recent Examples on the Web

The mortality stats also showed an increase in suicides, which have been rising steadily for nearly two decades and have been ranked as the tenth most common cause of death in the US since 2008. Cathleen O'grady, Ars Technica, "US life expectancy continues to move in reverse," 29 Nov. 2018 Last year, The Lancet reported an observational study of nearly 135,000 people demonstrating that those who ate the least saturated fat had higher rates of heart disease and early mortality; those who ate the most had the fewest strokes. Tamar Adler, Vogue, "Why Pastured Eggs Are the Perfect Food," 13 Sep. 2018 Experts estimate there are no more than 440 animals left on the planet, and the species’ future is bleak because of heavy mortality and poor reproduction in recent years. William J. Kole, The Seattle Times, "Simulator helps experts understand how whales get entangled," 21 Nov. 2018 People who received similar treatments to these recommendations had the lowest mortality among this group of patients. John Timmer, Ars Technica, "AIs trained to help with sepsis treatment, fracture diagnosis," 27 Oct. 2018 But research shows grip strength is a good predictor of overall strength, which in turn serves as a good predictor for overall health, with one recent study even finding an association between grip strength and lower mortality. SELF, "Why You Should Add Loaded-Carry Exercises to Your Strength Routine," 21 Oct. 2018 The series might find its home on a network geared toward a younger audience, but throughout its run, each eleven-minute episode has been packed with a surprising amount of heart, tackling subjects from mortality to consent. Lauren Rearick, Teen Vogue, ""Adventure Time" Showrunner Adam Muto and Olivia Olson on the Show's Legacy," 30 Aug. 2018 What's worse, that same recent report from the CDC highlights an association between opioid exposure and pre-term labor, stillbirth, even maternal mortality. . Hayley Krischer, Marie Claire, "How Heroin Came for Middle-Class Moms," 20 Aug. 2018 Black females begin to outnumber black males by age 16, Judice writes, partly as a result of high mortality and incarceration rates that Judice said result from systematic discrimination against black males. Heidi Stevens,, "Northwestern professor wants black women to look for love outside their race," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mortality.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of mortality

15th century, in the meaning defined at sense 1

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Statistics for mortality

Last Updated

9 Dec 2018

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The first known use of mortality was in the 15th century

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English Language Learners Definition of mortality

: the quality or state of being a person or thing that is alive and therefore certain to die : the quality or state of being mortal

: the death of a person, animal, etc.

: the number of deaths that occur in a particular time or place


mor·​tal·​i·​ty | \mȯr-ˈtal-ət-ē \
plural mortalities

Medical Definition of mortality 

1 : the quality or state of being mortal

2a : the number of deaths in a given time or place

b : the proportion of deaths to population : death rate

called also mortality rate

— compare fertility sense 2, morbidity sense 2

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More from Merriam-Webster on mortality

Rhyming Dictionary: Words that rhyme with mortality

Spanish Central: Translation of mortality

Nglish: Translation of mortality for Spanish Speakers

Britannica English: Translation of mortality for Arabic Speakers Encyclopedia article about mortality

Comments on mortality

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living or existing for a long time

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