coiling vs undulating

coiling

noun
  • The process of fitting a ship with electromagnetic coils, so that it can be degaussed while travelling. 

  • The pattern or motion of something that coils. 

undulating

noun
  • undulation 

adj
  • Forming a series of regular curves. 

  • Moving up and down like waves; wavy. 

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