con·fi·den·tial 
(kŏn′fĭ-dĕnshəl)
(kŏn′fĭ-dĕnshəl)adj.
1. Done or communicated in confidence; secret.
2. Entrusted with the confidence of another: a confidential secretary.
3. Denoting confidence or intimacy: a confidential tone of voice.
4. Containing information, the unauthorized disclosure of which poses a threat to national security.
con′fi·den′ti·ali·ty (-shē-ălĭ-tē), con′fi·dential·ness n.
con′fi·dential·ly adv.