dementia

American  

[dih-men-shuh, -shee-uh] / dɪˈmɛn ʃə, -ʃi ə /

noun

1. a condition characterized by progressive, persistent, severe impairment of intellectual capacity, including memory loss, confusion, and emotional instability, resulting from the loss of or damage to neurons in the brain.

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dementia British  

/ -ʃɪə, dɪˈmɛnʃə /

noun

1. a state of serious emotional and mental deterioration, of organic or functional origin

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dementia Scientific  

/ dĭ-mĕn′shə /

1. Deterioration of intellectual faculties, such as memory, concentration, and judgment, sometimes accompanied by emotional disturbance and personality changes. Dementia is caused by organic damage to the brain (as in Alzheimer's disease), head trauma, metabolic disorders, or the presence of a tumor.

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Other Word Forms

• demential adjective

Etymology

Origin of dementia

First recorded in 1800–10; from Latin dēmentia “madness,” equivalent to dēment- “out of one's mind” ( dement ) + -ia noun suffix

Compare meaning

How does dementia compare to similar and commonly confused words? Explore the most common comparisons:

• dementia vs. senility

Example Sentences

The study followed 793 adults who were an average of 39 years old and free of dementia at the beginning.

From Science Daily • Apr. 7, 2026

The researchers note that the findings show a relationship, not proof that vitamin D directly reduces tau levels or lowers the risk of dementia.

From Science Daily • Apr. 7, 2026

In a report published in December 2025, Alzheimer Scotland called for childhood dementia to be included in the Scottish government's national dementia strategy, alongside a nationally standardised framework of care and increased research investment.

From BBC • Mar. 31, 2026

Just before her fourth birthday Sophia Scott's parents were told she had a condition that causes childhood dementia.

From BBC • Mar. 31, 2026

Black men, women, and children suffering with everything from dementia and tuberculosis to “nervousness,” “lack of self-confidence,” and epilepsy were packed into every conceivable space, including windowless basement rooms and barred-in porches.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

Related Words

• brain damage
• mental disorder