attenuate vs clarify

attenuate

verb
  • To become thin or fine; to grow less. 

  • To reduce the amplitude of an electrical, radio, or optical signal. 

  • To weaken. 

  • To reduce in size, force, value, amount, or degree. 

  • To rarefy. 

  • (of a beer) To become less dense as a result of the conversion of sugar to alcohol. 

  • To reduce the virulence of a bacterium or virus. 

  • To make thinner, as by physically reshaping, starving, or decaying. 

adj
  • Gradually tapering into a petiole-like extension toward the base. 

clarify

verb
  • To grow clear or bright; to clear up. 

  • To make clear or easily understood; to explain in order to remove doubt or obscurity. 

  • To grow or become clear or transparent; to become free from feculent impurities, as wine or other liquid under clarification. 

  • To make clear or bright by freeing from feculent matter. 

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