di·min·ished capacity /də-'mi-nisht-/ n
1: an abnormal mental condition that renders a person unable to form the specific intent necessary for the commission of a crime (as first-degree murder) but that does not amount to insanity – called also diminished responsibility, partial insanity; compare insanity, irresistible impulse test, m'naghten test, substantial capacity test
2 a: a defense based on a claim of diminished capacity
b: the doctrine that diminished capacity may negate an element of a crime
◇ If diminished capacity is shown, negating an element of the crime with which a defendant is charged, the defendant can only be convicted of a lesser offense that does not include the element.
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.