dementia
noun
de·men·tia
di-ˈmen(t)-shə 
-shē-ə
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
The Journal of the American Medical AssociationExamples of dementia in a Sentence
This patient suffers from dementia.
a new study on age-related dementias
Recent Examples on the Web
Sedgwick's Cynthia is married to a man over two decades her senior, Warren (Judd Hirsch), who is rapidly declining into dementia.
—Maureen Lee Lenker, EW.com, 3 June 2025
And then there's specific activities that lower your risk for Parkinson's and dementia as well, including racket sports like table tennis and pickleball.
—Renée Onque, CNBC, 3 June 2025
Bill’s arthritis and early dementia have resulted in new, unexpected costs.
—Joseph Coughlin, Forbes.com, 2 June 2025
Current national data suggests that dementia rates in Asian Americans trend lower than other groups.
—Tom Gavin, EverydayHealth.com, 2 June 2025
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Maureen Lee Lenker, EW.com, 3 June 2025
And then there's specific activities that lower your risk for Parkinson's and dementia as well, including racket sports like table tennis and pickleball.
—Renée Onque, CNBC, 3 June 2025
Bill’s arthritis and early dementia have resulted in new, unexpected costs.
—Joseph Coughlin, Forbes.com, 2 June 2025
Current national data suggests that dementia rates in Asian Americans trend lower than other groups.
—Tom Gavin, EverydayHealth.com, 2 June 2025
See All Example Sentences for dementia
Cite this Entry
“Dementia.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dementia. Accessed 7 Jun. 2025.
Copy CitationKids Definition
dementia
noun
de·men·tia
di-ˈmen-chə
1
: a condition of the brain that is marked especially by a deterioration in the ability to think, reason, or remember
2
: a condition of deteriorating mental functioning
Medical Definition
dementia
noun
de·men·tia
di-ˈmen-chə
: 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)
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