sugar beet vs sugar-plum

sugar beet

noun
  • darling; sweetheart 

  • A type of beet whose root contains a high concentration of sucrose. 

sugar-plum

noun
  • Term of endearment: sweetheart, darling. 

  • A round or oval sweet/piece of candy made of boiled sugar. 

How often have the words sugar beet and sugar-plum occurred in a corpus of books? (source: Google Ngram Viewer )