conjoined vs united

conjoined

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

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

  • Combined. 

united

adj
  • Joined into a single entity. 

  • Involving the joint activity of multiple agents. 

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