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compos mentis

[kohm-pohs men-tis; English kom-puh s-men-tis] /ˈkoʊm poʊs ˈmɛn tɪs; English ˈkɒm pəsˈmɛn tɪs/
Latin. sane; mentally sound.
Origin of compos mentis
literally, being in full possession of one's mind

non compos mentis

[nohn kohm-pohs men-tis; English non kom-puh s men-tis] /ˈnoʊn ˈkoʊm poʊs ˈmɛn tɪs; English ˈnɒn ˈkɒm pəs ˈmɛn tɪs/
adjective, Latin.
not of sound mind; mentally incapable of managing one's affairs. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for compos mentis
Historical Examples
  • Look here, old fellow, do you mean to assert that you are compos mentis?

    Witness to the Deed George Manville Fenn
  • Men acting under the guidance of factions are not compos mentis.

    Miles Wallingford James Fenimore Cooper
  • Lunacy is often the development of one idea, while, in other respects, the patient is compos mentis.

    The Man with a Shadow George Manville Fenn
  • His son is non compos mentis, and thereby incapable of making any conveyance in law; so that all his measures are disappointed.

    Love for Love William Congreve
  • compos mentis, kom′pos ment′is, adj. phrase, in one's right mind—sometimes merely Compos.

British Dictionary definitions for compos mentis

compos mentis

/ˈkɒmpəs ˈmɛntɪs/
(postpositive) of sound mind; sane

non compos mentis

/ˈnɒn ˈkɒmpəs ˈmɛntɪs/
mentally incapable of managing one's own affairs; of unsound mind
Word Origin
Latin: not in control of one's mind
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for compos mentis

Latin, literally "in command of one's mind;" from compos "having the mastery of," from com- "with" (see com-) + stem of potis "powerful, master" (see potent); + mentis, genitive of mens "mind" (see mind (n.)).

non compos mentis

Latin, literally "not master of one's mind."

Online Etymology Dictionary, © 2010 Douglas Harper
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compos mentis in Medicine

compos mentis com·pos men·tis (kŏm'pəs měn'tĭs)
Of sound mind; sane.

non compos mentis non com·pos men·tis (nŏn kŏm'pəs měn'tĭs)
Not of sound mind and hence not legally responsible; mentally incompetent.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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compos mentis in Culture
non compos mentis [(non kom-puhs men-tis)]

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.”

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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