confidential

/ˌkɑːnfɪˈdenʃəl/
adjective
  1. Intended to be kept secret or private; not to be shared with others.
    • She spoke in a confidential tone so no one else could hear.
    • The lawyer kept all client conversations confidential.
    • Please mark this document as confidential before sending it.
  2. Trusted with private or secret information.
    • He works as a confidential assistant to the CEO.
    • Only confidential staff members have access to the files.
    • The diplomat's confidential secretary handled all sensitive messages.
Antonyms
What does "confidential" mean? | whatsthatwordmean | whatsthatwordmean