break off vs disunite

break off

verb
  • To remove a piece from a whole by breaking or snapping 

  • To end abruptly, either temporarily or permanently. 

  • To end a relationship. 

disunite

verb
  • To separate, sever, or split. 

  • To cause disagreement or alienation among or within. 

  • To disintegrate; to come apart. 

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