The Collaborative International Dictionary of English v.0.48:
Confidential \Con`fi*den"tial\, a. [Cf. F. confidentiel.]
1. Enjoying, or treated with, confidence; trusted in;
trustworthy; as, a confidential servant or clerk.
2. Communicated in confidence; secret. "Confidential
Confidential communication (Law) See Privileged
communication, under Privileged.
Confidential creditors, those whose claims are of such a
character that they are entitled to be paid before other
Confidential debts, debts incurred for borrowed money, and
regarded as having a claim to be paid before other debts.