sugar-plum vs sweet pea

sugar-plum

noun
  • Term of endearment: sweetheart, darling. 

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

sweet pea

noun
  • A term of endearment for something sweet or lovely; a child or an intimate partner, for example. 

  • A flowering plant, Lathyrus odoratus, grown for its bright colours and sweet fragrance. 

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