se·​nes·​cence | \ si-ˈne-sᵊn(t)s How to pronounce senescence (audio) \

Definition of senescence

1 : the state of being old : the process of becoming old
2 : the growth phase in a plant or plant part (such as a leaf) from full maturity to death

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Other Words from senescence

senescent \ si-​ˈne-​sᵊnt How to pronounce senescent (audio) \ adjective

Did You Know?

Senescence can be traced back to Latin senex, meaning "old." Can you guess which other English words come from senex? Senile might come to mind, as well as senior. But another one might surprise you: senate. This word for a legislative assembly dates back to ancient Rome, where the Senatus was originally a council of elders composed of the heads of patrician families. There's also the much rarer senectitude, which, like senescence, refers to the state of being old (specifically, to the final stage of the normal life span).

Examples of senescence in a Sentence

Recent Examples on the Web The researchers compared cells extracted from between the tree wood and bark and found that there was no change in the expression of genes related to biological aging, called senescence. Katie Hunt, CNN, "Some trees can live for more than 1,000 years and scientists may have figured out why," 14 Jan. 2020 Every time cells divide, telomeres shorten—and when telomeres have been sufficiently shaved away, cells enter a state called senescence and stop dividing. Katherine Ellen Foley, Quartz, "A biotech startup thinks its idea could cure dementia—but scientists have their doubts," 14 Jan. 2020 As expected, the expression of genes associated with senescence, the final and fatal stage of life, increased predictably in dying leaves. Erin Malsbury, Science | AAAS, "How the Ginkgo biloba achieves near-immortality," 13 Jan. 2020 And unless they get arrested and put into jail, they may be doomed to homelessness in their senescence. Jay Newton-small, Time, "How to Keep Alzheimer’s From Bringing About the Zombie Apocalypse," 20 Nov. 2019 Year after year, from childhood through senescence, our birthdays are accompanied by turkeys and fruitcake and mistletoe. Mary Schmich,, "Column: Here’s to the holiday birthday babies, who get neglected in this busy time of year," 8 Nov. 2019 Over time, as animals age, more and more cells enter senescence, a process that's thought to contribute to aging. John Timmer, Ars Technica, "Drugs that kill off old cells may limit a body’s aging," 10 July 2018 These seemingly unrelated features of senescence are manifestations of a common underlying phenomenon: declining bioresilience. WSJ, "Is There a Limit to the Human Lifespan?," 24 June 2018 Rarely before has the senescence of this Senate — which, with an average age of 63, is the oldest in history — been so apparent. Nash Jenkins, Time, "The Mark Zuckerberg vs. Ted Cruz Showdown Was the Most Explosive Part of Today's Facebook Testimony," 10 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'senescence.' 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 senescence

1695, in the meaning defined at sense 1

History and Etymology for senescence

senescent, from Latin senescent-, senescens, present participle of senescere to grow old, from sen-, senex old

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Time Traveler for senescence

Time Traveler

The first known use of senescence was in 1695

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Cite this Entry

“Senescence.” Dictionary, Merriam-Webster, Accessed 10 Jul. 2020.

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More Definitions for senescence


How to pronounce senescence (audio)

English Language Learners Definition of senescence

technical + formal : the state of being old or the process of becoming old


se·​nes·​cence | \ si-ˈnes-ᵊn(t)s How to pronounce senescence (audio) \

Medical Definition of senescence

: the state of being old : the process of becoming old

More from Merriam-Webster on senescence

Thesaurus: All synonyms and antonyms for senescence

Britannica English: Translation of senescence for Arabic Speakers

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