from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Not of sound mind and hence not legally responsible; mentally incompetent.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Insane; not of sound mind; not in control of one's self.
from The Century Dictionary and Cyclopedia
- n. Not capable, mentally, of managing one's own affairs; not of sound mind; not having the normal use of reason. Often abbreviated non compos and non comp. See insane.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. not of sound mind, memory, or understanding; in law, not competent to go to trial
Latin nōn compos mentis : nōn, not + compos, in control + mentis, genitive sing. of mēns, mind.(American Heritage® Dictionary of the English Language, Fourth Edition)