sneaky

sneaky
    adj 1: marked by deception; "achieved success in business only
           by underhand methods" [syn: {sneaky}, {underhand},
           {underhanded}]
    2: 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"
       [syn: {furtive}, {sneak(a)}, {sneaky}, {stealthy},
       {surreptitious}]
    

Sneaky \Sneak"y\, n.
   Like a sneak; sneaking.
   [1913 Webster]
    

92 Moby Thesaurus words for "sneaky":
      Machiavellian, Machiavellic, acute, arch, artful, astute,
      back-door, backstairs, cagey, calculating, canny, chiseling,
      clandestine, clever, collusive, covert, covinous, cowering, crafty,
      cringing, cunning, cute, deceitful, deep, deep-laid, designing,
      devious, diplomatic, dishonest, disingenuous, duplicitous, false,
      falsehearted, feline, finagling, foxy, fraudulent, furtive,
      guileful, hidlings, hole-and-corner, hugger-mugger, indirect,
      ingenious, insidious, inventive, knowing, pawky, politic, privy,
      quailing, quiet, ready, resourceful, scheming, serpentine, sharp,
      shifty, shrewd, skulking, slick, slinking, slinky, slippery, sly,
      smooth, snaky, sneaking, sophistical, stealthy, strategic, subtile,
      subtle, supple, surreptitious, tactical, treacherous, trickish,
      tricksy, tricky, two-faced, under-the-counter, under-the-table,
      undercover, underground, underhand, underhanded, unobtrusive,
      unscrupulous, vulpine, wary, wily