非公開|ひこうかいhikoukai[2]nakadaka (mid-high)

1. no-adjectiveprivate; non-public; secret; closed-door; closed

• Synonym秘密ひみつNeutralRefers to things kept from others' knowledge; 「非公開」 is about not releasing or showing something to the public.
• Synonym内々うちうちNeutralDoing things only among insiders; works in both speech and writing, as in 「内々に打診する」. 「非公開」 is the formal term for not being open to the public.
• Synonym内密ないみつWrittenWritten style, meaning keeping something confidential. 「非公開」 is about not being open to the public.
• Synonym内緒ないしょCasualColloquial, for keeping something from others, as in 「内緒の話」; 「非公開」 is the formal word for closed to the public.
• Related隠密おんみつWrittenWritten style, for acting in secret; can also mean a spy. 「非公開」 just means not open to the public.
• Related秘め事ひめごとWrittenWritten style for hidden matters kept from others. 「非公開」 is about information not being made public.
• Antonym公開こうかいNeutralMaking something public or open to all; the direct opposite of 「非公開」.
• Antonym公表こうひょうWrittenWritten style for officially announcing something publicly; the opposite of 「非公開」.
• AntonymオープンCasualA loanword meaning open or public; the opposite of 「非公開」.

Use 「非公開」 for information or meetings kept from the public, as in 「非公開会議」. For a secret use 「秘密」; in casual speech, hiding something is 「内緒」. The opposites are 「公開」 and 「公表」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 一般いっぱんの人ひとには公開こうかいしないこと。