attach vs sever

attach

verb
  • To connect, in a figurative sense; to ascribe or attribute; to affix; with to. 

  • To adhere; to be attached. 

  • To win the heart of; to connect by ties of love or self-interest; to attract; to fasten or bind by moral influence; with to. 

  • To come into legal operation in connection with anything; to vest. 

  • To fasten, to join to (literally and figuratively). 

sever

verb
  • To make a separation or distinction; to distinguish. 

  • To disconnect; to disunite; to terminate. 

  • To cut free. 

  • To suffer disjunction; to be parted or separated. 

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