1 : the next to highest level of official classification for documents
2 : conducted with or marked by hidden aims or methods; "clandestine intelligence operations"; "cloak-and-dagger activities behind enemy lines"; "hole-and-corner intrigue"; "secret missions"; "a secret agent"; "secret sales of arms"; "surreptitious mobilization of troops"; "an undercover investigation"; "underground resistance"
3 : having a secret or hidden meaning; "cabalistic symbols engraved in stone"; "cryptic writings"; "thoroughly sibylline in most of his pronouncements"- John Gunther
4 : (of information) given in confidence or in secret; "this arrangement must be kept confidential"; "their secret communications"
adjectif
1 : official classification of information or documents; withheld from general circulation
