clear up vs illuminate

clear up

verb
  • To clarify, to correct a misconception. 

  • To depart or disappear. 

  • To clean up. 

  • To become free of certain blemishes. 

  • Of stormy weather, to dissipate, to become calm. 

  • To pot all of the remaining balls in a single turn. 

illuminate

verb
  • To clarify or make something understandable. 

  • To be exposed to light. 

  • To shine light on something. 

  • To glow; to light up. 

  • To decorate the page of a manuscript book with ornamental designs. 

  • To decorate something with lights. 

  • To make spectacular. 

  • To direct a radar beam toward. 

noun
  • Someone thought to have an unusual degree of enlightenment. 

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