accessary vs helpful

accessary

adj
  • Accompanying as a subordinate; additional; accessory; especially, uniting in, or contributing to, a crime, but not as chief actor. See accessory. 

noun
  • Someone who accedes to some act, now especially a crime; one who contributes as an assistant or instigator to the commission of an offense. 

helpful

adj
  • Furnishing help; giving aid; useful. 

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