dementia

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noun de·men·tia \ di-ˈmen(t)-shə , -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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demential

play \-shəl\ adjective

See dementia defined for English-language learners

See dementia defined for kids

Examples of dementia in a Sentence

This patient suffers from dementia.
a new study on age-related dementias

Recent Examples of dementia from the Web

Some U.S. studies have suggested that generations better educated than their grandparents have somewhat less risk of dementia.

— lauran neergaard, The Seattle Times, "Lifestyle changes may help stave off Alzheimer’s," 20 July 2017
But by ninety-five, his quick wit was softened by dementia, his critical eye replaced by a sweet and goofy demeanor, and fits of paranoia.

— kate axelrod, Longreads, "The Condition that Shielded My Grandfather From Heartbreak," 15 July 2017
A separate program arranges classes and activities for people in the early to middle stages of dementia.

— james barron, New York Times, "At a Chelsea Art Gallery, an Age Requirement: Over 60 Only," 9 July 2017
Metcalf died in Cutler Bay June 23 at 95 of vascular dementia, Ng said.

— elizabeth koh, miamiherald, "A Florida lawmaker defied ‘grandmotherly’ image," 29 June 2017
HI, CAROLYN: My father is in the early stages of dementia, and his controlling and critical side has turned into him just being mean.

— carolyn hax, The Seattle Times, "Ways to cope with a nasty Dad who has dementia," 26 June 2017
There's the cancer with secret, environmental roots, the lies that spouses tell, the encroachments of dementia and the near-absence of any actual civility beneath the veneer of money.

— beth kephart, chicagotribune.com, "Review: Julia Fierro's 'The Gypsy Moth Summer' echoes 'Gatsby'," 26 June 2017
Fred Shuttlesworth and Abraham Woods to protest the bond grant to Bobby Frank Cherry - one of the bombers of the 16th Street Baptist Church - who had at that time been deemed unfit to stand trial due to advanced dementia.

— erin edgemon, AL.com, "Community activist Frank Matthews announces run for Birmingham mayor," 19 June 2017
My dad is dead and my mom has dementia and can’t remember or articulate the past.

— diana whitney, Longreads, "My Father’s Adventure Was My Terror," 19 June 2017

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.

Origin and Etymology of dementia

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

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First Known Use: 1806

See Words from the same year

dementia Synonyms

Synonyms

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

Antonyms

mind, saneness, sanity

Related Words

neurosis, psychosis; instability, irrationality, unreasonableness; delirium, frenzy, hysteria; hallucinosis, hypomania, paranoia, schizophrenia; senile dementia; delusion, hallucination; monomania, obsession, phobia; abnormality, dementedness, unsoundness

Near Antonyms

lucidity, rationality, rationalness, reasonability, reasonableness; normality, soundness

Other Psychology Terms

fetish, hypochondria, intelligence, mania, narcissism, neurosis, pathological, psychosis, schadenfreude, subliminal

Medical Dictionary

dementia

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noun de·men·tia \ di-ˈmen-chə \

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)

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