backshore vs littoral

backshore

noun
  • An upper shore zone above high-tide. 

littoral

noun
  • The zone of a coast between high tide and low tide levels. 

  • A shore. 

adj
  • Of or relating to the shore, especially the seashore. 

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