non compos mentis

adjective

non com·​pos men·​tis ˌnän-ˌkäm-pəs-ˈmen-təs 

ˌnōn-

: not of sound mind

Synonyms

• balmy
• barmy [chiefly British]
• bats
• batty
• bedlam
• bonkers
• brainsick
• bughouse [slang]
• certifiable
• crackbrained
• cracked
• crackers
• crackpot
• cranky [dialect]
• crazed
• crazy
• cuckoo
• daffy
• daft
• demented
• deranged
• fruity [slang]
• gaga
• haywire
• insane
• kooky
• kookie
• loco [slang]
• loony
• looney
• loony tunes
• looney tunes
• lunatic
• mad
• maniacal
• maniac
• mental
• meshuga
• meshugge
• meshugah
• meshuggah
• moonstruck
• nuts
• nutty
• psycho
• psychotic
• scatty [chiefly British]
• screwy
• unbalanced
• unhinged
• unsound
• wacko
• whacko
• wacky
• whacky
• wud [chiefly Scottish]

Examples of non compos mentis in a Sentence

will seek to prove that the elderly tycoon was non compos mentis when he dictated that will

Word History

Etymology

Latin, literally, not having mastery of one's mind

First Known Use

1607, in the meaning defined above

Medical Definition

non compos mentis

adjective

non com·​pos men·​tis ˌnän-ˌkäm-pə-ˈsment-əs, ˌnōn- 

: not of sound mind

Legal Definition

non compos mentis

adjective

non com·​pos men·​tis ˈnän-ˈkäm-pəs-ˈmen-təs 

: not of sound mind : lacking mental ability to understand the nature, consequences, and effect of a situation or transaction

Etymology

Latin, literally, not having mastery of one's mind