(sand) dunes vs coast

(sand) dunes

coast

noun
  • The edge of the land where it meets an ocean, sea, gulf, bay, or large lake. 

verb
  • To sail along a coast. 

  • To glide along without adding energy; to allow a vehicle to continue moving forward after disengaging the engine or ceasing to apply motive power. 

  • To make a minimal effort; to continue to do something in a routine way, without initiative or effort. 

  • To slide downhill; to slide on a sled upon snow or ice. 

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