Synonyms: stealthy, surreptitious, sneak, sneaky, furtive
Definition: marked by quiet and caution and secrecy; taking pains to avoid being observed
Usage: a furtive manner; a sneak attack; stealthy footsteps; a surreptitious glance at his watch
Similar words: concealed
Definition: hidden on any grounds for any motive
Usage: a concealed weapon; a concealed compartment in his briefcase