call a halt vs sever

call a halt

verb
  • Force (something) to stop. 

sever

verb
  • To disconnect; to disunite; to terminate. 

  • To make a separation or distinction; to distinguish. 

  • To cut free. 

  • To suffer disjunction; to be parted or separated. 

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