apropos vs knowing

apropos

adj
  • by the way, incidental 

  • Of an appropriate or pertinent nature. 

prep
  • Regarding or concerning. 

adv
  • To the purpose; appropriately. 

  • By the way. 

  • Timely; at a good time. 

knowing

adj
  • Deliberate, wilful. 

  • The ability to know something without being taught. 

  • Suggestive of private knowledge or understanding. 

  • Possessing knowledge or understanding; knowledgeable, intelligent. 

  • Shrewd or showing clever awareness; discerning. 

  • Demonstrating knowledge of what is in fashion; stylish, chic. 

noun
  • The act or condition of having knowledge. 

prep
  • Given my knowledge about someone or something. 

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