spoken, written, acted on, etc., in strict privacy or secrecy; secret: a confidential remark.
indicating confidence or intimacy; imparting private matters: a confidential tone of voice.
having another's trust or confidence; entrusted with secrets or private affairs: a confidential secretary.
bearing the classification confidential, usually being above restricted and below secret.
limited to persons authorized to use information, documents, etc., so classified. Compare classification ( def 5 )
confidentiality, confidentialness, noun
restricted, private. 2.
intimate, familiar. 3.
trusted, trustworthy, private. See familiar