sly vs knavish

sly and knavish both are adjectives.

Word	Noun	Adjective	Verb	Adverb
sly	No	Yes	No	No
knavish	No	Yes	No	No

As adjectives, sly and knavish are synonyms defined as:

Other synonyms of sly include crafty, cunning, dodgy, foxy, guileful, slick, tricksy, tricky, wily.

sly (adjective)	knavish (adjective)
marked by skill in deception	marked by skill in deception