foxiness vs slyness

foxiness and slyness both are nouns.

Word	Noun	Adjective	Verb	Adverb
foxiness	Yes	No	No	No
slyness	Yes	No	No	No

As nouns, foxiness and slyness are synonyms defined as:

foxiness and slyness: shrewdness as demonstrated by being skilled in deception

Other synonyms of foxiness include craft, craftiness, cunning, guile, wiliness.

foxiness (noun)	slyness (noun)
shrewdness as demonstrated by being skilled in deception	shrewdness as demonstrated by being skilled in deception