add vs sever

add

verb
  • To sum up; to put together mentally; to add up. 

  • To append (e.g. a statement); to say further information; to add on. 

  • To summon minions or reinforcements. 

  • To combine elements of (something) into one quantity. 

  • To give by way of increased possession (to someone); to bestow (on). 

  • To make an addition; to augment; to increase; to add on. 

  • To join or unite (e.g. one thing to another, or as several particulars) so as to increase the number, augment the quantity, or enlarge the magnitude, or so as to form into one aggregate. 

  • To perform the arithmetical operation of addition. 

noun
  • The addition of a song to a station's playlist. 

  • An act or instance of adding. 

  • An additional enemy that joins a fight after the primary target. 

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 add and sever occurred in a corpus of books? (source: Google Ngram Viewer )