fad vs impulse

fad

noun
  • A phenomenon that becomes popular for a very short time. 

impulse

noun
  • A wish or urge, particularly a sudden one prompting action. 

  • A thrust; a push; a sudden force that impels. 

  • The integral of force over time. 

verb
  • To impel; to incite. 

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