Containing information, the unauthorized disclosure of which poses a threat to national security.
Operating in a hidden or confidential manner:
Kept within certain limits; limited:
Secret, not spoken of (spoken of only in hushed whispers between insiders).
A classified is defined as an ad in a paper.
Find another word for top-secret. In this page you can discover 10 synonyms, antonyms, idiomatic expressions, and related words for top-secret, like: confidential, secret, restricted, kept quiet, hush-hush, classified, highly classified, supersecret, under security restrictions and under-wraps.