lilac vs purpure

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. 

purpure

adj
  • In blazon, of the colour purple. 

noun
  • A purple colour on a coat of arms, represented in engraving by diagonal parallel lines 45 degrees clockwise. 

  • purpure 

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