stealthy


stealthy (http://definr.com/stealthy)

     adj : marked by quiet and caution and secrecy; taking pains to
           avoid being observed; "a furtive manner"; "a lurking
           prowler"; "a sneak attack"; "stealthy footsteps"; "a
           surreptitious glance at his watch"; "someone skulking
           in the shadows" [syn: furtive, lurking, skulking,
            sneak(a), sneaky, surreptitious]