coalesce vs cojoin

coalesce

verb
  • To merge, to intermingle freely. 

  • To form from different pieces or elements. 

  • To bond pieces of metal into a continuous whole by liquefying parts of each piece, bringing the liquids into contact, and allowing the combined liquid to solidify. 

  • To join into a single mass or whole. 

cojoin

verb
  • To join together; to conjoin. 

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