demented

Past participle of dement, from Latin dēmentāre.

• IPA^(key): /dɪˈmɛntɪd/

demented (comparative more demented, superlative most demented)

1. Insane or mentally ill.
   • 2012 August 5, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “I Love Lisa” (season 4, episode 15; originally aired 02/11/1993)”, in (Please provide the book title or journal name)‎:

     So while Ralph generally seems to inhabit a different, more glorious and joyful universe than everyone else here his yearning and heartbreak are eminently relateable. Ralph sometimes appears to be a magically demented sprite who has assumed the form of a boy, but he’s never been more poignantly, nakedly, movingly human than he is here.

2. Suffering from dementia.
3. (informal) Crazy; ridiculous.

   a demented idea

demented

1. simple past tense and past participle of dement

• mentally ill