con·fi·den·tial /ˌkän-fi-'den-chəl/ adj1: known or conveyed only to a limited number of peoplea confidential disclosure2: marked by or indicative of intimacy, mutual trust, or willingness to confide esp. between parties one of whom is in a position of superioritythe confidential relationship of doctor and patient3: containing information whose unauthorized disclosure could be prejudicial to the national interestcon·fi·den·ti·al·i·ty /ˌkän-fi-ˌden-chē-'a-lə-tē/ ncon·fi·den·tial·ly adv
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.
arcane, arcanus, auricular, classified, concealed, fidus, hidden, imparted in secret, irrevealable, not for publication, not to be communicated, not to be disclosed, not to be quoted, not to be spoken of, off the record, private, restricted, secret, spoken in confidence, told in confidence, top-secret, undercover, unmentionable, unrevealed
associated concepts: confidential communication, confidential information, confidential proceeding, confidential relationship, fiduciary relationship, privilege
clandestine, close (intimate), collusive, esoteric, fiduciary, intimate, personal (private), privy, secret
Burton's Legal Thesaurus. William C. Burton. 2006
Particularly in close trading relationships, giving access to confidential information and trade secrets to trading partners can be risky. A duty to keep such material confidential can be imposed. This needs to be in respect of keeping information secret, preventing disclosure to third parties or being used with a view to going into competition. A separate confidentiality agreement or a term in another agreement should address such issues both during and after the relationship.
Easyform Glossary of Law Terms. — UK law terms.
The Essential Law Dictionary. — Sphinx Publishing, An imprint of Sourcebooks, Inc. Amy Hackney Blackwell. 2008.