scallywag vs knave

scallywag and knave both are nouns.

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

As nouns, scallywag and knave are synonyms defined as:

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

scallywag (noun)	knave (noun)
one who is playfully mischievous	one of four face cards in a deck bearing a picture of a young prince
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)