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

Other semi-public spaces, including El Secreto and La Cava, were either not ready for guests or so top secret as to elude me. —Paul Brady, Travel + Leisure, 18 Sep. 2025

Everything was so under wraps, especially our legacy cast members — super top secret. —Emily Longeretta, Variety, 4 Sep. 2025

All the actors were scanned using Google’s next generation top secret scanning stage. —Melanie Goodfellow, Deadline, 1 Sep. 2025

While most college coaches treat their practices like a top secret meeting, Dykes has maintained a wide-open media policy, allowing reporters to watch full practices in the spring and fall camps, and even allowing fans and media to watch entire scrimmages. —Steven Johnson, Fort Worth Star-Telegram, 29 Aug. 2025

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