From Longman Dictionary of Contemporary Englishdiminished responsibilitydiˌminished responsiˈbility (also diminished capacity American English) noun [uncountable] law SCLSCLMPwhen someone is not considered to be responsible for their actions because they are mentally ill
Examples from the Corpus
diminished responsibility• Capper admitted manslaughter on the grounds of diminished responsibility.• He's denied murdering Elizabeth Howe, but has admitted manslaughter on the grounds of diminished responsibility.• He pleaded guilty to manslaughter on the grounds of diminished responsibility.• The 1977 Homicide Act introduced the notion of diminished responsibility, which reduces a charge of murder to manslaughter.• It was surely only people of diminished responsibility who found their lives being taken over in this way.• This will now allow a plea of diminished responsibility.• Ryman, of Spalding, Lincs, admitted manslaughter with diminished responsibility and was jailed for five years. 