/ Dictionary / Index N non compos mentis*: Meaning and Definition of Find definitions for: non com•pos men•tis Pronunciation: (nōn' kōm'pōs men'tis Eng. non' kom'p&schwas men'tis), [key] — Latin. Latin. not of sound mind; mentally incapable of managing one's affairs. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. non compos nonconcurrence Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language