billow vs rippling

billow

noun
  • A large wave, swell, surge, or undulating mass of something, such as water, smoke, fabric or sound 

verb
  • To surge or roll in billows. 

  • To swell out or bulge. 

rippling

noun
  • A motion or sound that ripples. 

adj
  • Moving in a chaotic, undulating fashion, as in a flow of water or a flag blowing in the wind. 

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