Formal term for official disapproval or rejection, often used in administrative, legal, or institutional contexts.
申請は不認可となった。
The application was rejected.
計画は当局の不認可を受けた。
The plan received disapproval from the authorities.
却下 is a more common term for rejection, especially of a motion or application, while 不認可 is more formal and often implies a higher authority's disapproval.
Compound of 不 (fu, 'not') and 認可 (ninka, 'approval'), forming a formal noun meaning 'disapproval' or 'rejection'.