confidential

American  

[kon-fi-den-shuhl] / ˌkɒn fɪˈdɛn ʃəl /

adjective

1. spoken, written, acted on, etc., in strict privacy or secrecy; secret.

   a confidential remark.

   Synonyms:

   private, restricted

2. indicating confidence or intimacy; imparting private matters.

   a confidential tone of voice.

   Synonyms:

   familiar, intimate

3. having another's trust or confidence; entrusted with secrets or private affairs.

   a confidential secretary.

   Synonyms:

   private, trustworthy

4. (of information, a document, etc.)

   1. bearing the classification confidential, usually being above restricted and below secret.

   2. limited to persons authorized to use information, documents, etc., so classified.

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confidential British  

/ ˌkɒnfɪˈdɛnʃəl /

adjective

1. spoken, written, or given in confidence; secret; private

2. entrusted with another's confidence or secret affairs

   a confidential secretary

3. suggestive of or denoting intimacy

   a confidential approach

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Related Words

See familiar.

Other Word Forms

• confidentiality
  noun
• confidentially
  adverb
• confidentialness
  noun
• nonconfidential
  adjective
• nonconfidentiality
  noun
• nonconfidentially
  adverb
• nonconfidentialness
  noun
• quasi-confidential
  adjective
• quasi-confidentially
  adverb

Etymology

Origin of confidential

First recorded in 1645–55; from Latin confīdenti(a) confidence + -al ¹

Explanation

If you get a letter stamped confidential, that means you're not supposed to tell anyone else what it says. It's private and you're not supposed to blab about it. Confidential suggests that you're being let in on a secret — as in Kitchen Confidential, the title of a book by Anthony Bourdain, a famous chef, in which he tells unappetizing stories about the restaurant industry. If you confide in someone, you are trusting him or her with confidential or secret information. Choose your confidants wisely!

Example Sentences

“The Department of Justice also knows that these confidential informants helped law enforcement put violent extremists in jail.”

From Los Angeles Times • May 1, 2026

“We must surely be very tough about this,” one British diplomat wrote in a confidential 1966 memo to colleagues.

From The Wall Street Journal • Apr. 28, 2026

Reitzes envisions that AI-related subscriptions “may not be as easy to understand as those known to SaaS,” since details of long-term agreements and so-called strategic collaboration agreements are confidential.

From MarketWatch • Apr. 27, 2026

SpaceX filed confidential paperwork with the Securities and Exchange Commission in late March or early April, according to reports.

From Barron's • Apr. 27, 2026

Keeping patient information confidential was emerging as a standard practice, but it wasn’t law, so releasing it wasn’t out of the question.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

Related Words

• classified
• hush-hush
• intimate
• private