- dementia⇄dementia, noun.
a partial or complete deterioration of mind.
Ex. (Figurative.) Tied up in costly appeal proceedings, ... Bruce became a mad, abject figure, a classic instance of litigant's dementia (New York Times).
(SYN) insanity, luna - dementia⇄senile psychosis ordementia
a mental disorder caused by atrophy of the brain due to old age, characterized by loss of memory, depression, confusion, delusions, and irrational behavior.