percolate vs precipitation

percolate

noun
  • A liquid that has been percolated. 

verb
  • To pass a liquid through a porous substance; to filter. 

  • To make (coffee) in a percolator. 

  • To drain or seep through a porous substance. 

  • To spread slowly or gradually; to slowly become noticed or realised. 

precipitation

noun
  • A reaction that leads to the formation of a heavier solid in a lighter liquid; the precipitate so formed at the bottom of the container. 

  • Any or all of the forms of water particles, whether liquid or solid, that fall from the upper atmosphere (e.g., rain, hail, snow or sleet). It is a major class of hydrometeor, but it is distinguished from cloud, fog, dew, rime, frost, etc., in that it must fall. It is distinguished from cloud and virga in that it must reach the ground. 

  • A hurried headlong fall. 

  • Unwise or rash rapidity; sudden haste. 

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