chestnut vs lilac

chestnut

noun
  • A nut of this tree or shrub. 

  • A round or oval horny plate found on the inner side of the leg of a horse or other animal, similar to a birthmark on a human. 

  • A tree or shrub of the genus Castanea. 

  • The wood of a chestnut tree. 

  • A dark, reddish-brown colour, as seen on the fruit of the chestnut tree. 

  • A reddish-brown horse. 

  • An old joke; a worn-out meme, phrase, ploy, etc. so often repeated as to have grown tiresome or ineffective (often in the phrase "old chestnut"). 

  • The horse-chestnut. 

adj
  • Of a deep reddish-brown colour, like that of a chestnut. 

lilac

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. 

adj
  • Having a pale purple colour. 

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