downcome vs labefaction

downcome

noun
  • A tumbling or falling down; a sudden or heavy fall; an overthrow; ruin; destruction. 

  • In ironmaking, a pipe that leads combustible gases downward from the top of the blast furnace to the hot-blast stoves, boilers, etc., where they are burned. 

  • A downpour of rain. 

verb
  • To come down; fall down; come or fall apart. 

labefaction

noun
  • The act of shaking or weakening or the resulting state; overthrow, ruination. 

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