se·​nes·​cent si-ˈne-sᵊnt How to pronounce senescent (audio)
: relating to, characterized by, or associated with the state of being old or the process of aging : marked by or undergoing senescence
senescent foliage
The "sandwich generation"—caught between adolescent children and senescent parents …The Economist
… researchers have opened up a novel approach to combating the effects of aging with the discovery that a special category of cells, known as senescent cells, are bad actors that promote the aging of the tissues.Nicholas Wade

Examples of senescent in a Sentence

Recent Examples on the Web If the cells were truly senescent, then the medications should both reduce the number of senescent cells and reverse many of the structural DNA changes and gene expression disruptions. Megan Molteni, STAT, 9 Jan. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'senescent.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from Latin senēscent-, senēscens, present participle of senēscere "to grow old, age, deteriorate, slacken off, be in decline," from sen-, senex "old, aged, old man" + -ēsc-, suffix of inchoative verbs — more at senior entry 2

First Known Use

1656, in the meaning defined above

Time Traveler
The first known use of senescent was in 1656

Dictionary Entries Near senescent

Cite this Entry

“Senescent.” Dictionary, Merriam-Webster, Accessed 2 Dec. 2023.

Medical Definition


se·​nes·​cent si-ˈnes-ᵊnt How to pronounce senescent (audio)
: relating to, characterized by, undergoing, or associated with senescence
Senescent cells secrete a variety of factors but scientists still do not fully understand the role senescent cells play in many physiological processes …Science
During ageing, molecular chaperones such as heat-shock proteins are thought to combat stress-related senescent dysfunction.Marc Tatar et al., Nature

More from Merriam-Webster on senescent

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