basin vs plunge pool

basin

noun
  • A rock formation scooped out by water erosion. 

  • An area of land from which water drains into a common outlet; drainage basin. 

  • A wide bowl for washing, sometimes affixed to a wall. 

  • A depression, natural or artificial, containing water. 

verb
  • To serve as or become a basin. 

  • To shelter or enclose in a basin. 

  • To create a concavity or depression in. 

plunge pool

noun
  • A pool that is small in diameter, but deep, usually resulting from erosion by a natural force such as a waterfall or rapids. 

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