curvy vs undulating

curvy

adj
  • Having curves. 

  • Buxom or curvaceous. 

  • Overweight. 

undulating

adj
  • Forming a series of regular curves. 

  • Moving up and down like waves; wavy. 

noun
  • undulation 

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