1.Definition: (of information) given in confidence or in secret
"Their secret communications"
2.Definition: communicated covertly
"Their secret signal was a wink", "Secret messages"
3.Definition: conducted with or marked by hidden aims or methods
"Secret missions", "A secret agent", "Secret sales of arms"
4.Definition: designed to elude detection
"A secret passage", "The secret compartment in the desk"
5.Definition: having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding
"The secret learning of the ancients"
7.Definition: indulging only covertly
"A secret alcoholic"
8.Definition: not expressed
"Secret (or private) thoughts"
9.Definition: not open or public; kept private or not revealed
"A secret formula", "Secret ingredients", "Secret talks"
10.Definition: not openly made known
"A secret marriage", "A secret bride"
11.Definition: the next to highest level of official classification for documents