de·​men·​tia | \ di-ˈmen(t)-shə How to pronounce dementia (audio) , -shē-ə \

Definition of dementia

1 : a usually progressive condition (such as Alzheimer's disease) marked by the development of multiple cognitive deficits (such as memory impairment, aphasia, and the inability to plan and initiate complex behavior) dementia is diagnosed only when both memory and another cognitive function are each affected severely enough to interfere with a person's ability to carry out routine daily activities.The Journal of the American Medical Association
2 : madness, insanity a fanaticism bordering on dementia

Other Words from dementia

demential \ di-​ˈmen(t)-​shəl How to pronounce dementia (audio) , -​shē-​əl \ adjective

Synonyms & Antonyms for dementia



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Examples of dementia in a Sentence

This patient suffers from dementia. a new study on age-related dementias
Recent Examples on the Web Garner, who has dementia, allegedly tried to steal less than $15 worth of goods from the store. CBS News, 6 May 2022 Time is all that Alice and the Father have left together, yet it cannot be maximized through the haze of his dementia. Hua Hsu, The New Yorker, 29 Apr. 2022 Judy Brannon, 73, who has dementia, watched the team and picked up on some of their moves. Alex Groth, Milwaukee Journal Sentinel, 13 Apr. 2022 Miller, who lives in Michigan, had been in Kherson taking care of her grandmother, who has dementia and cannot walk, when the war broke out and Russian troops occupied their city. Los Angeles Times, 10 Apr. 2022 Trudy’s elderly owner lived alone and had dementia. Annette Mcgivney, Outside Online, 4 Apr. 2022 Her husband, who has dementia, cannot share her fears and worries. Washington Post, 17 Mar. 2022 Faced with the reality of his impending mortality, Ptolemy lives alone in squalor, unable to overcome the frightening and dizzying haze of his dementia. NBC News, 13 Mar. 2022 Hoarding is a mental disorder, and can accompany dementia. New York Times, 23 Apr. 2022 See More

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

First Known Use of dementia

1806, in the meaning defined at sense 1

History and Etymology for dementia

borrowed from Latin dēmentia "derangement, insanity, folly," noun derivative of Latin dēment-, dēmens "out of one's mind, frenzied, insane," from dē- de- + -ment, -mens, adjective derivative of ment-, mens "power of reason, mental balance, mind" — more at mind entry 1

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Time Traveler for dementia

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The first known use of dementia was in 1806

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Dictionary Entries Near dementia



dementia praecox

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Statistics for dementia

Last Updated

9 May 2022

Cite this Entry

“Dementia.” Dictionary, Merriam-Webster, Accessed 20 May. 2022.

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More Definitions for dementia


de·​men·​tia | \ di-ˈmen-chə How to pronounce dementia (audio) \

Medical Definition of dementia

: a usually progressive condition (as Alzheimer's disease) marked by the development of multiple cognitive deficits (as memory impairment, aphasia, and inability to plan and initiate complex behavior)

Other Words from dementia

demential \ -​chəl How to pronounce dementia (audio) \ adjective

More from Merriam-Webster on dementia

Nglish: Translation of dementia for Spanish Speakers

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


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