run off vs slope off

run off

verb
  • To flee or depart quickly. 

  • To operate by a particular energy or fuel source. 

  • to have diarrhea 

  • To make photocopies, or print. 

  • To write something quickly. 

  • To pour or spill off or over. 

  • To cause to flow away. 

  • To chase someone away. 

slope off

verb
  • To depart quietly, without being noticed. 

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