senility

noun

se·​nil·​i·​ty si-ˈni-lə-tē How to pronounce senility (audio)
also se-
Synonyms of senilitynext
sometimes offensive
: the quality or state of being senile : the physical and mental decline associated with old age
especially : the deterioration of cognitive functioning associated with old age

Note: Senility is now typically avoided in medical contexts and may be considered offensive in general contexts because of its negative implication that cognitive decline is part of the normal aging process. Dementia is usually considered the appropriate term to use when describing the serious progressive cognitive decline that most commonly affects older adults.

Synonyms of senility

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Examples of senility in a Sentence

with his increasing senility, Granddad is beginning to have more and more senior moments
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.
Salles doesn’t clarify his viewpoint until the end, when Eunice ages into senility. — Armond White, National Review, 7 Feb. 2025 Is Chuck Schumer headed down the same dark treadmill to senility pioneered by Dementia Joe Biden before him? — Howie Carr, Boston Herald, 29 Mar. 2026 Then the interview happens, and Thomas is swinging between lucidity and senility, and a million things about their relationship come up, and the fiction records the interview the phone couldn’t capture. — Andrew Marantz, New Yorker, 5 Apr. 2026 As populations’ median ages continue to rise — and the future looks increasingly hazardous for all age groups — more movies are touching on senility, dementia, elder abuse and other topics that not long ago rarely got any screen airing. — Dennis Harvey, Variety, 11 Mar. 2025 See All Example Sentences for senility

Word History

First Known Use

1652, in the meaning defined above

Time Traveler
The first known use of senility was in 1652

Rhymes for senility

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Browse Nearby Words

senilely
senility
senior
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Cite this Entry

“Senility.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/senility. Accessed 7 Jul. 2026.

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Kids Definition

senility

noun
se·​nil·​i·​ty si-ˈnil-ət-ē How to pronounce senility (audio)
: the quality or state of being senile
especially : a decline in mental abilities that is associated with old age

Medical Definition

senility

noun
se·​nil·​i·​ty
si-ˈnil-ət-ē also se-
plural senilities
: the quality or state of being senile : the physical and mental decline associated with old age
especially : the deterioration of cognitive functioning associated with old age

Note: Due to its negative implication that cognitive decline is part of the normal aging process, use of the term senility is now typically avoided in medical contexts and may be considered offensive in general contexts. Dementia is usually considered the appropriate term to use when describing the serious progressive cognitive decline that most commonly affects older adults.

More from Merriam-Webster on senility

Nglish: Translation of senility for Spanish Speakers

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