alighten vs unlight

alighten

verb
  • To alight, to dismount or get down from. 

  • To make light; to illuminate or brighten. 

  • To lighten; to reduce in weight or heaviness. 

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

unlight

verb
  • To alight; dismount 

  • To extinguish, turn off, or dim the light from 

noun
  • The absence of light; darkness. 

adj
  • Not light (“having little weight”). 

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