slyness

In uncountable|lang=en terms the difference between guile and slyness

is that guile is (uncountable) astuteness often marked by a certain sense of cunning or artful deception while slyness is (uncountable) the state or quality of being being sly.

As nouns the difference between guile and slyness

is that guile is (uncountable) astuteness often marked by a certain sense of cunning or artful deception while slyness is (uncountable) the state or quality of being being sly.

As a verb guile

is to deceive, to beguile.