sneaky

(s) marked by deception
- achieved success in business only by underhand methods
underhanded, underhand,
(s) 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
furtive, sneak, stealthy, surreptitious,

underhanded underhand furtive sneak stealthy surreptitious

Snead sneak