1. (v. t.) Dexterous in performing an action, so as to escape notice; nimble; skillful; cautious; shrewd; knowing; -- in a good sense.

2. (v. t.) Artfully cunning; secretly mischievous; wily.

3. (v. t.) Done with, and marked by, artful and dexterous secrecy; subtle; as, a sly trick.

4. (v. t.) Light or delicate; slight; thin.

5. (adv.) Slyly.

Byzantine Machiavellian Machiavellic acute adroit arch artful astute back-door backstairs cagey calculating canny clandestine clever covert crafty creep crooked cunning cute deceitful deep deep-laid designing devious dexterous diplomatic dishonest disingenuous downy feline foxy furtive guileful gumshoe hidlings hole-and-corner hugger-mugger ingenious insidious inventive knowing lurk masterful pawky politic predatory privy quiet ready resourceful scheming serpentine shady sharp shifty shrewd skulk skulking slick slide slim slink slinking slinky slippery smart smooth snake snaky sneaking sneaky snook sophistical steal stealthy strategic subtile subtle supple surreptitious tactical trickish tricksy tricky under-the-counter under-the-table undercover underground underhand underhanded unfrank unobtrusive unscrupulous vulpine wary wily