dilly-dally vs fluctuate

dilly-dally

verb
  • To dawdle; to waste time; to procrastinate. 

fluctuate

verb
  • To undulate. 

  • To cause to vary irregularly. 

  • To vary irregularly; to swing. 

  • To be irresolute; to waver. 

How often have the words dilly-dally and fluctuate occurred in a corpus of books? (source: Google Ngram Viewer )