plash vs plunge pool

plash

noun
  • A small pool of standing water; a puddle. 

  • A splash, or the sound made by a splash. 

  • A sudden downpour. 

  • The branch of a tree partly cut or bent, and bound to, or intertwined with, other branches. 

verb
  • To cut partly, or to bend and intertwine the branches of. 

  • To splash or sprinkle with colouring matter. 

  • To cause a splash. 

  • To bend down a bough (in order to pick fruit from it). 

  • To splash. 

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 plash and plunge pool occurred in a corpus of books? (source: Google Ngram Viewer )