demented

adjective

de·​ment·​ed di-ˈmen-təd 

1

: mad, insane

The advertising campaign for the movie version is trying to sell it as a prankish comedy, with the eccentric aunt who appears from nowhere as a demented Mary Poppins.

—Pauline Kael

… the violence was instigated directly by Serbian nationalists in Bosnia and in Belgrade as part of their demented project to separate the two intermixed ethnic communities once and for all,

—Charles Simic

2

: affected by or exhibiting cognitive dementia

At least one-third of people serving as caregivers for a demented husband or wife become chronically depressed.

—Bennett D. Gurian

dementedly adverb

dementedness noun

Synonyms

• balmy
• barmy [chiefly British]
• bats
• batty
• bedlam
• bonkers
• brainsick
• bughouse [slang]
• certifiable
• crackbrained
• cracked
• crackers
• crackpot
• cranky [dialect]
• crazed
• crazy
• cuckoo
• daffy
• daft
• deranged
• fruity [slang]
• gaga
• haywire
• insane
• kooky
• kookie
• loco [slang]
• loony
• looney
• loony tunes
• looney tunes
• lunatic
• mad
• maniacal
• maniac
• mental
• meshuga
• meshugge
• meshugah
• meshuggah
• moonstruck
• non compos mentis
• nuts
• nutty
• psycho
• psychotic
• scatty [chiefly British]
• screwy
• unbalanced
• unhinged
• unsound
• wacko
• whacko
• wacky
• whacky
• wud [chiefly Scottish]

Examples of demented in a Sentence

Many of the patients there were demented.

In the movie, he plays a demented man trying to survive on the streets of Los Angeles.

Her demented ramblings are a symptom of her illness.

He gave me a demented little smile.

parents who are almost demented with worry

Recent Examples on the Web

Christmas Evil plays like a demented piece of outsider art that takes the idea of a killer Santa to some pretty extreme places — including an ending that has to be seen to be believed. —Keith Phipps, Vulture, 5 Dec. 2024

Watching him dance and sing with a room full of demented goblins never really gets old. —Ollie Barder, Forbes, 25 Nov. 2024

What begins as a seeming act of kindness on Steven’s part soon turns into a truly demented version of Sophie’s Choice. —Jennifer M. Wood, WIRED, 29 Oct. 2024

Lucky for Michele, Laurel starts to break down, incapable of finding the will to continue this demented game of Royal Match. —Emma Sharpe, Vulture, 6 Nov. 2024

Word History

Etymology

from past participle of dement "to deprive of reason, drive mad," borrowed from Medieval Latin dēmentāre, going back to Late Latin, "to deceive, hoodwink," verbal derivative of Latin dēment-, dēmens "out of one's mind, frenzied, insane" — more at dementia

First Known Use

1632, in the meaning defined at sense 1

Kids Definition

demented

adjective

de·​ment·​ed di-ˈment-əd 

: mentally disordered

dementedly adverb

Medical Definition

demented

adjective

de·​ment·​ed di-ˈment-əd 

: affected by or exhibiting cognitive dementia

dementedly adverb

dementedness noun