alluvion vs mischance

alluvion

noun
  • The increase in the area of land due to the deposition of sediment (alluvium) by a river. 

mischance

noun
  • Bad luck, misfortune. 

  • A mishap, an unlucky circumstance. 

verb
  • To undergo (a misfortune); to suffer (something unfortunate). 

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