Guile is cleverness used to trick or deceive someone. A person with guile knows how to get what they want through cunning rather than honesty. In the folktale of the Gingerbread Man, the fox uses guile to trick the cookie into climbing onto his nose, where he can finally eat him. The fox doesn't use force or speed; he uses clever deception.

Think of guile as a kind of sneaky intelligence. A student who uses guile might convince others to do their share of a group project by making elaborate excuses. A character in a story might use guile to sweet-talk their way past a guard. The word suggests someone is being manipulative, working an angle, or playing others for fools.

Guileful describes someone who regularly uses this kind of trickery, while guileless means the opposite: innocent, honest, and straightforward. A guileless person says exactly what they mean and trusts that others will do the same. When someone calls another person guileless, they often mean it as a compliment, suggesting the person is refreshingly honest in a world where guile is common.