Dementia

[dɪ'menʃə] or [dɪ'mɛnʃə]

(noun.) mental deterioration of organic or functional origin.

Inputed by Glenda--From WordNet

(n.) Insanity; madness; esp. that form which consists in weakness or total loss of thought and reason; mental imbecility; idiocy.

Typed by Connie

n. [L.] (Med.) Idiocy, insanity, loss of intellect.

Inputed by Cecile

n. general mental enfeeblement with loss of memory reason feeling and will: often the consequence of acute mania.

Inputed by Bennett