Definition of compos mentis in English:

compos mentis

adjective

  • [predicative] Having full control of one's mind.

    ‘are you sure he was totally compos mentis?’
    • ‘Even though anyone still living who saw them play is probably not adequately compos mentis to remember the occasion.’
    sensible, well adjusted, reasonable, rational, level-headed, sound, practical, discerning, logical, able to think clearly, lucid, clear-headed, coherent
    View synonyms

Origin

Early 17th century: Latin.

Pronunciation:

compos mentis

/ˌkɒmpɒs ˈmɛntɪs/