dementia

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

|Updated on: 16 Jun 2018

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

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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

Fitness has long been seen as an antidote to the development of dementia.

— emiko jozuka, CNN, "In the 'land of the immortals': Japan's centenarian pop band," 8 June 2018
Increasingly, researchers are exploring other pathways to treat the deadly form of dementia.

— stacey burling, Philly.com, "An asthma drug shows promise against Alzheimer's," 8 June 2018
Alzheimer’s, Lewy Body, Vascular, & Frontotemporal are types of dementia.

— kristen cusato, sandiegouniontribune.com, "ABC’s of Alzheimer’s and dementia for caregivers," 4 June 2018
Another step people can take to improve cognitive function and help reduce their risk of dementia is to find something that challenges their way of thinking, McDonald said.

— patricia dillon, Houston Chronicle, "Brain health emphasized during Alzheimer’s and Brain Awareness Month," 2 June 2018
Not getting enough exercise is linked to a number of health problems, including obesity, heart disease, diabetes and even some forms of dementia.

— alice park, Time, "Getting a Lot of Physical Activity at Work May Actually Be Bad For You," 14 May 2018
Who hasn't been touched in some way by some form of dementia?

— linda gandee/special to cleveland.com, cleveland.com, "Alzheimer's Night of a Thousand Lights brings together those searching for answers; guest speaker said we are gaining on this," 14 May 2018
My mother, who was in the early stages of dementia, was none the wiser, and kept calling him Father.

— roberta brown, Vogue, "Why I Left My Life as a Nun and Became a Sex Therapist," 2 May 2018
That Charleston's former Saints teammate Mike McKenzie, just nine years into retirement, is already showing signs of dementia, according to McKenzie's wife.

— mike scott, NOLA.com, "Former Saints player Jeff Charleston airs brain disease concerns on 'Southern Charm New Orleans'," 30 Apr. 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.

Origin and Etymology of dementia

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

NEW! Time Traveler

First Known Use: 1806

in the meaning defined at sense 1

See Words from the same year

Other Psychology Terms

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

Medical Dictionary

dementia

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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