beat off vs fight off

beat off

verb
  • To drive something away with blows or military force. 

  • To waste time. 

  • To masturbate, usually a man of himself. 

fight off

verb
  • To succeed in defeating a challenge, or an attack. 

  • To resist, particularly an infection or an emotion. 

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