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" - cloak and dagger- hole and corner- hugger mugger- hush hush
marked by quiet and caution and secrecy
taking pains to avoid being observed "a furtive manner" "a sneak attack" "stealthy footsteps" "a surreptitious glance at his watch"