billow vs haystack

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. 

haystack

noun
  • A standing wave in a rapid. 

  • A dish composed of a starchy food (rice, tortillas, crackers, etc.) topped by a protein (beans, cheese, meat, etc.) in combination with fresh vegetables, assembled on the plate by the diner. 

  • A mound, pile, or stack of stored hay. 

  • The text string within which another string is searched for. (see: needle in a haystack) 

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