disunite vs uncouple

disunite

verb
  • To disintegrate; to come apart. 

  • To cause disagreement or alienation among or within. 

  • To separate, sever, or split. 

uncouple

verb
  • To come loose. 

  • To disconnect or detach one thing from another. 

  • To loose, as dogs, from their couples. 

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