segregate vs split off

segregate

verb
  • To separate, especially by social policies that directly or indirectly keep races or ethnic groups apart. 

adj
  • Separated from others of the same kind. 

  • Separate from a mass and collected together along lines of fraction. 

  • Separate; select. 

split off

verb
  • To break away from a group or mass. 

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