slip, sneak -- (pass on stealthily; "He slipped me the key when nobody was looking")
Overview of adj sneak
The adj sneak has 1 sense
furtive, sneak, sneaky, stealthy, surreptitious -- (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")