(uncountable) The property of being confidential. / (countable) Something told in confidence; a secret.

Kept, or meant to be kept, secret within a certain circle of persons; not intended to be known publicly

In a confidential manner. / Spoken of in a private manner.

The state or quality of being confidential.

plural of confidentiality

plural of confidential informant

(law enforcement) A person who secretly provides information to the police about wrongdoing which they are aware of due to their relationship to the wrongdoer.