THESAURUS
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