alighten vs dismount

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. 

dismount

verb
  • To come down; to descend. 

  • To throw (cannon) off their carriages. 

  • To make (a mounted drive) unavailable for use. 

  • To (cause to) get off (something). 

noun
  • The part of a routine in which the gymnast detaches from an apparatus. 

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