prune vs sever

prune

verb
  • To cut down or shorten (by the removal of unnecessary material). 

  • To remove excess material from a tree or shrub; to trim, especially to make more healthy or productive. 

  • To remove unnecessary branches from a tree data structure. 

  • To become wrinkled like a dried plum, as the fingers and toes do when kept submerged in water. 

noun
  • The dried, wrinkled fruit of certain species of plum. 

  • Something wrinkly like a prune. 

  • An old woman, especially a wrinkly one. 

sever

verb
  • To cut free. 

  • To disconnect; to disunite; to terminate. 

  • To make a separation or distinction; to distinguish. 

  • To suffer disjunction; to be parted or separated. 

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