Definition of Secret

Adjective: secret see-krut

Not open or public; kept private or not revealed
"a secret formula"; "secret ingredients"; "secret talks"
Conducted with or marked by hidden aims or methods
"secret missions"; "a secret agent"; "secret sales of arms";
- clandestine, cloak-and-dagger, hole-and-corner, hugger-mugger, hush-hush, surreptitious, undercover, underground
Not openly made known
"a secret marriage";
- unavowed
Communicated covertly
"their secret signal was a wink"; "secret messages"
Not expressed
"secret thoughts";
- private
Designed to elude detection
"a secret passage"; "the secret compartment in the desk";
- hidden
Hidden from general view or use
"a secret garden";
- privy, secluded
(of information) given in confidence or in secret
"their secret communications";
- confidential
Indulging only covertly
"a secret alcoholic"
Having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding
"the secret learning of the ancients";
- mysterious, mystic, mystical, occult, orphic
The next to highest level of official classification for documents

Noun: secret see-krut

Something that should remain hidden from others (especially information that is not to be passed on)
"the combination to the safe was a secret"; "he tried to keep his drinking a secret"
Information known only to a special group
"the secret of Cajun cooking";
- arcanum
Something that baffles understanding and cannot be explained
"it remains one of nature's secrets";
- mystery, enigma, closed book