Webster's Revised Unabridged Dictionary · 1913

Dement

Dement , transitive verb

[Latin dementare, from demens, -mentis, out of one's mind, mad; de + mens mind. See Mental, and compare Dementate.]

To deprive of reason; to make mad. [Rare] — Bale

Dement , adjective

[Latin demens, - mentis.]

Demented; dementate. [Rare] — J. H. Newman