coalesce vs sever

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. 

sever

verb
  • To suffer disjunction; to be parted or separated. 

  • To disconnect; to disunite; to terminate. 

  • To make a separation or distinction; to distinguish. 

  • To cut free. 

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