converge vs intercross

converge

verb
  • (said of two or more entities) To approach each other; to get closer and closer. 

  • (said of a sequence or series) To have a (finite, proper) limit. 

  • (said of an iterative process) To reach a stable end point. 

intercross

verb
  • To cross back over one another 

  • To breed two strains having a common ancestry with one another 

noun
  • The act or product of intercrossing 

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