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

Royce Williams, who is eligible to receive the Medal of Honor for his 1952 dogfight against seven Soviet MiGs, which was classified top secret for more than 50 years. —Linda McIntosh, San Diego Union-Tribune, 26 Feb. 2026

Soviet involvement was top secret at the time, so the records of the event were classified for decades. —James Laporta, CBS News, 24 Feb. 2026

However, specific plot and character details are being kept top secret for now — including whether any former cast members will return. —Sydney Bucksbaum, Entertainment Weekly, 29 Jan. 2026

Therefore, their work, whether from menial day-to-day tasks to top secret missions for national security are consistently linked back to the overarching mission of defending their country. —Heather V. MacArthur, Forbes.com, 22 Jan. 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