Pronunciation: (in-san'i-tē), [key]
1. the condition of being insane; a derangement of the mind.
2. Law.such unsoundness of mind as affects legal responsibility or capacity.
3. Psychiatry.(formerly) psychosis.
4. extreme folly; senselessness; foolhardiness.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.