alluvion vs drencher

alluvion

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

drencher

noun
  • One who, or that which, drenches. 

  • A fire prevention device, like a sprinkler but ejecting a denser curtain of water and sometimes mounted on the outside of a building to prevent the spread of fire from those nearby. 

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