illuminant vs incandescent

illuminant

noun

  • Something that illuminates. 

adj

  • That illuminates. 

incandescent

noun

  • An incandescent lamp or bulb 

adj

  • Showing intense emotion, as of a performance, etc. 

  • Emitting light as a result of being heated. 

  • Shining very brightly. 

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