top secret

adjective

1

: protected by a high degree of secrecy

a top secret weapon

a top secret meeting

2

a

: containing or being information whose unauthorized disclosure could result in exceptionally grave danger to the nation

top secret messages

compare confidential, secret

b

: of or relating to top secret documents

a top secret clearance

Examples of top secret in a Sentence

The mission is top secret.

Recent Examples on the Web

Is there a category that is above top secret that even those in the highest echelons don’t know about it? — Mikey O'Connell, HollywoodReporter, 10 Aug. 2026

The planning and details of the meeting were supposed to be kept top secret because of its highly sensitive nature. — Martha Ross, Mercury News, 7 Aug. 2026

The country singer, 53, attended the July 3 nuptials with his wife, Kimberly Williams-Paisley, after the couple received their invite with top secret instructions. — Leigh Blickley, Entertainment Weekly, 20 July 2026

Taylor Swift and Travis Kelce’s wedding was so top secret that even one of their celebrity guests, Pat McAfee, initially thought his digital invitation was a scam. — Juliana Ukiomogbe, InStyle, 15 July 2026

Word History

First Known Use

1942, in the meaning defined at sense 1

Kids Definition

top secret

adjective

1

: protected by a high degree of secrecy

a top secret meeting

2

: containing information that is very important to the safety and defense of a nation

top secret messages