lixiviate vs seep

lixiviate

verb
  • To separate (a substance) into soluble and insoluble components through percolation; to leach. 

adj
  • Impregnated with salts from wood ashes. 

  • Of or relating to lye or lixivium; of the quality of alkaline salts. 

noun
  • leachate 

seep

verb
  • To ooze or pass slowly through pores or other small openings, and in overly small quantities; said of liquids, etc. 

  • (of a crack etc.) To allow a liquid to pass through, to leak. 

  • To enter or penetrate slowly; to spread or diffuse. 

  • To diminish or wane away slowly. 

noun
  • The seeping away of a liquid, etc. 

  • A seafloor vent. 

  • Moisture, liquid, gas, etc. that seeps out; a seepage. 

  • A small spring, pool, or other spot where liquid from the ground (e.g. water, petroleum or tar) has oozed to the surface; a place of seeping. 

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