də̇ˈmench]ə, also ]ēə noun
( -s )
Etymology: Latin, from dement-, demens mad + -ia — more at dement
1. : a condition of deteriorated mentality that is characterized by marked decline from the individual's former intellectual level and often by emotional apathy — contrasted with amentia
2. : madness
the dementia of national hatreds — Times Literary Supplement
Synonyms: see insanity