Simple Definition of top secret
: kept completely secret by high government officials
Full Definition of top secret
1 : protected by a high degree of secrecy <a top secret weapon> <a top secret meeting>
2a : containing or being information whose unauthorized disclosure could result in exceptionally grave danger to the nation <top secret messages> — compare confidential, secretb : of or relating to top secret documents <a top secret clearance>
Examples of top secret
The mission is top secret.
First Known Use of top secret
Seen and Heard
What made you want to look up top secret? Please tell us where you read or heard it (including the quote, if possible).