conjoined vs synergic

conjoined

adj
  • Joined or bound together; united (in a relationship) 

  • Joined together physically, of persons (conjoined twins), or things. 

  • Combined. 

synergic

adj
  • Of or pertaining to synergy; synergistic 

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