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

Coppola snatches unassimilated ideas from current political paranoia and recent cultural catastrophes (manic news media promoting celebrity insanity), all tossed into the mix with demented incoherence. —Armond White, National Review, 4 Oct. 2024

In the sequel, co-written by Phillips and Scott Silver, Joker meets his demented muse, Harley Quinn, while serving time for murder at Arkham Asylum. —Rebecca Rubin, Variety, 1 Oct. 2024

Sánchez’s entry features industrious zombies hot on the tails of some cyclists, while Evans’ installment (the best here) deals with a demented doomsday cult. —Declan Gallagher, EW.com, 13 Sep. 2024

Half a century later, the scene seems no less appalling, given the way Stanley Kubrick made such ultraviolence look like fun for the demented kids who were doing it. —Peter Debruge, Variety, 31 Aug. 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