1. confidential

entrusted with private information and the confidence of another

Example Sentences:
'a confidential secretary'

2. confidential, secret

(of information) given in confidence or in secret

Example Sentences:
'this arrangement must be kept confidential'
'their secret communications'

• secret

3. confidential

denoting confidence or intimacy

Example Sentences:
'a confidential approach'
'in confidential tone of voice'

4. confidential

the level of official classification for documents next above restricted and below secret; available only to persons authorized to see documents so classified