knocking vs philippic

knocking

noun
  • An act in which something is knocked on, or the sound thus produced 

  • A repetitive ping, knock, or similar sound coming from an engine in which there are repeated uncontrolled explosions in the combustion chamber. 

philippic

noun
  • Any of the discourses of Demosthenes against Philip II of Macedon, defending the liberty of Athens. 

  • Any tirade or declamation full of bitter condemnation. 

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