nondisclosure; concealment of facts
Refers to the act of not informing someone about something, often used in legal, medical, or business contexts where disclosure is expected.
The doctor chose nondisclosure to the patient.
The contract includes a nondisclosure clause.
非公開 means 'not open to the public' or 'private', while 不告知 specifically refers to the act of not informing someone.
Compound of 不 (fu, 'not') and 告知 (kokuchi, 'notification, announcement'). The exact historical derivation is uncertain, but the word follows a common Sino-Japanese pattern for negation.