Definition of sly

• v. t. - Dexterous in performing an action, so as to escape notice; nimble; skillful; cautious; shrewd; knowing; -- in a good sense.
• v. t. - Artfully cunning; secretly mischievous; wily.
• v. t. - Done with, and marked by, artful and dexterous secrecy; subtle; as, a sly trick.
• v. t. - Light or delicate; slight; thin.
• adv. - Slyly.