- Obs. insanity; madness
- Psychiatry a disorder of the mind affecting perception, memory, and judgment, characterized by reduced ability to remember, control muscular movements, recognize familiar objects and sounds, etc.
Origin of dementiaL, insanity ; from demens: see dement
Origin of dementiaLatin d&emacron;mentia, madness, from d&emacron;m&emacron;ns, d&emacron;ment-, senseless; see dement.
(usually uncountable, plural dementias)