alighten vs illuminate

alighten

verb
  • To make light; to illuminate or brighten. 

  • To lighten; to reduce in weight or heaviness. 

  • To alight, to dismount or get down from. 

  • To alight; to land, to descend and rest. 

illuminate

verb
  • To glow; to light up. 

  • To be exposed to light. 

  • To shine light on something. 

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

  • To decorate something with lights. 

  • To clarify or make something understandable. 

  • To make spectacular. 

  • To direct a radar beam toward. 

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

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