non compos mentis

[ nohn kohm-pohs men-tis; English non kom-puhs men-tis ]

adjective

, Latin.

1. not of sound mind; mentally incapable of managing one's affairs (used especially in a legal context). Compare compos mentis ( def ).

non compos mentis

/ ˈnɒn ˈkɒmpəs ˈmɛntɪs /

adjective

1. mentally incapable of managing one's own affairs; of unsound mind

non compos mentis

1. A phrase used to describe someone who is out of his or her mind and therefore not legally responsible for his or her actions: “It was determined by the court that the killer was non compos mentis.” From Latin , meaning “not having control of the mind.”

Word History and Origins

Origin of non compos mentis¹

Latin: not in control of one's mind