lilac vs purpurate

lilac

adj
  • Having a pale purple colour. 

noun
  • A flower of the lilac shrub. 

  • A pale purple color, the color of some lilac flowers. 

  • A large shrub of the genus Syringa, especially Syringa vulgaris, bearing white, pale-pink, or purple flowers. 

purpurate

adj
  • Of a purple colour. 

noun
  • A salt of purpuric acid. 

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