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

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Other Words from dementia

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

Synonyms & Antonyms for dementia


aberration, derangement, insanity, lunacy, madness, mania, rage [archaic]


mind, saneness, sanity

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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

And the country’s Paro robot, a therapeutic bot that mimics a baby harp seal, is used in nursing homes to engage and entertain dementia patients. James Vincent, The Verge, "Japan’s latest home robot isn’t useful — it’s designed to be loved," 20 Dec. 2018 Click to Read Story To Help Alzheimer’s Patients, a Care Center Recreates the 1950s A new California care facility for dementia patients, was built to resemble a town from the 1950s. Sumathi Reddy, WSJ, "A Lab Tests Playing to Help Children With Autism," 26 Nov. 2018 One study that tried circadian lighting with dementia patients living at home found that caregivers also slept better. Stacey Burling,, "The era of circadian lighting in health care is dawning," 27 June 2018 While drugmaker Avanir Pharmaceuticals has said that many dementia patients suffer from PBA, regulators are concerned that Medicare may be paying for the drug for unapproved and potentially fraudulent uses. Blake Ellis And Melanie Hicken, CNN, "Government issues warning about pill pushed on the elderly," 4 June 2018 In households where dementia patients have access to firearms, the doctors raised concerns about suicides, accidental shootings, theft and unauthorized use of guns. Melissa Healy,, "As more older Americans struggle with dementia, what happens to their guns?," 11 May 2018 Brightly colored fixtures can make the bathroom easier to navigate, and quite possibly safer, not just for dementia patients but for anyone who’s less than fully alert in the morning. Susannah Gardiner, Smithsonian, "Could Our Housewares Keep Us Healthier?," 3 May 2018 This book tells many of the problems associated with the care of a dementia patient. idahostatesman, "Caregiver’s diary, homage to St. John’s cathedral are new books out by local authors | Idaho Statesman," 14 Apr. 2018 These visitors came from many walks of life, but most were residents of a local adult care home for dementia patients in Essen. Sally Mcgrane, New York Times, "In Germany, the Power of Art in the Twilight of Life," 21 Mar. 2018

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.

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First Known Use of dementia

1806, in the meaning defined at sense 1

History and Etymology for dementia

Latin, from dement-, demens mad, from de- + ment-, mens mind — more at mind

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Statistics for dementia

Last Updated

23 Apr 2019

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Time Traveler for dementia

The first known use of dementia was in 1806

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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 demential (audio) \ adjective

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Comments on dementia

What made you want to look up dementia? Please tell us where you read or heard it (including the quote, if possible).


not to be persuaded, moved, or stopped

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