countenance vs prevent

countenance

verb
  • To tolerate, support, sanction, patronise or approve of something. 

noun
  • Appearance, especially the features and expression of the face. 

  • Favour; support; encouragement. 

  • Calm facial expression, composure, self-control. 

prevent

verb
  • To stop (an outcome); to keep from (doing something). 

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