Skip to main content
Find a Lawyer
Please enter a legal issue and/or a location
Begin typing to search, use arrow keys to navigate, use enter to select
FindLaw Legal Dictionary

The FindLaw Legal Dictionary -- free access to over 8260 definitions of legal terms. Search for a definition or browse our legal glossaries.



insanity n


: unsoundness of mind or lack of the ability to understand that prevents one from having the mental capacity required by law to enter into a particular relationship, status, or transaction or that releases one from criminal or civil responsibility: as
a : a disease, defect, or condition of the mind that renders one unable to understand the nature of a criminal act or the fact that it is wrong or to conform one's conduct to the requirements of the law being violated
b : inability to understand and participate in legal proceedings brought against one
: incompetence
c : inability to understand the nature and purpose of a punishment (as the death penalty) to which one has been sentenced
d : inability to understand the nature and consequences of one's acts (as making a will) or of events, matters, or proceedings in which one is involved see also commitment, durham rule, irresistible impulse test, m'naghten test, not guilty by reason of insanity, substantial capacity test compare capacity, competency, competent, diminished capacity, sanity
2 : the affirmative defense of having acted while insane

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.

Copied to clipboard

Find a Lawyer

More Options