cunning vs knavish

cunning is a noun but knavish is not a noun.

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

As adjectives, cunning and knavish are synonyms defined as:

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

cunning (noun)	knavish (noun)
crafty artfulness (especially in deception)
shrewdness as demonstrated by being skilled in deception

cunning (adjective)	knavish (adjective)
showing inventiveness and skill	marked by skill in deception
marked by skill in deception
attractive especially by means of smallness or prettiness or quaintness