conserve vs marmalade

conserve

noun
  • A jam or thick syrup made from fruit. 

  • Wilderness where human development is prohibited. 

verb
  • To protect an environment, heritage, etc. 

  • To remain unchanged during a process 

  • To save for later use, sometimes by the use of a preservative. 

marmalade

noun
  • A kind of jam made with citrus fruit, distinguished by being made slightly bitter by the addition of the peel and by partial caramelisation during manufacture. Most commonly made with Seville oranges, and usually qualified by the name of the fruit when made with other types of fruit. 

verb
  • To spread marmalade on. 

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