| Adj. | 1. | clandestine - 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"covert - secret or hidden; not openly practiced or engaged in or shown or avowed; "covert actions by the CIA"; "covert funding for the rebels" | |