blackguard vs picaro

blackguard

verb
  • To act like a blackguard; to be a scoundrel. 

  • To revile or abuse in scurrilous language. 

noun
  • The lowest servant in a household charged with pots, pans, and other kitchen equipment. 

picaro

noun
  • Rogue, adventurer. 

How often have the words blackguard and picaro occurred in a corpus of books? (source: Google Ngram Viewer )