knave vs scallywag

knave and scallywag both are nouns.

Word	Noun	Adjective	Verb	Adverb
knave	Yes	No	No	No
scallywag	Yes	No	No	No

As nouns, knave and scallywag are synonyms defined as:

Other synonyms of knave include rapscallion, rascal, rogue, scalawag, varlet.

knave (noun)	scallywag (noun)
one of four face cards in a deck bearing a picture of a young prince	one who is playfully mischievous
a deceitful and unreliable scoundrel	a deceitful and unreliable scoundrel
	a white Southerner who supported Reconstruction policies after the American Civil War (usually for self-interest)