alluvion vs contretemps

alluvion

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

contretemps

noun
  • An ill-timed pass. 

  • An unforeseen, inopportune, or embarrassing event. 

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