flump vs plunk

flump

verb
  • To drop something heavily or with a dull sound. 

  • To move or fall heavily, or with a dull sound. 

noun
  • A type of large marshmallow. 

  • A fat out-of-shape person. 

  • The dull sound so produced. 

plunk

verb
  • To drop or throw something heavily onto or into something else, so that it makes a dull sound. 

  • To pluck and quickly release (a musical string). 

  • To be a truant from (school). 

  • To intentionally hit the batter with a pitch. 

  • To croak. 

  • To land suddenly or heavily; to plump down. 

noun
  • The dull thud of something landing on a surface. 

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