ding-dong vs groundnut

ding-dong

noun
  • A penis. 

  • An idiot. 

  • A woman's breast. 

  • An attachment to a clock by which the quarter hours are struck upon bells of different tones. 

  • A fight, an argument; a set-to. 

  • A sound made by a bell. 

adj
  • Closely fought. 

verb
  • To ring with two tones, like a bell swinging back and forth. 

groundnut

noun
  • The nutlike tuber of such a plant, especially peanuts. 

  • A climbing vine, Apios americana, of eastern North America, having fragrant brownish flowers and small edible tubers. 

  • A plant which bears its nutlike seeds underground, such as a peanut (Arachis hypogaea) or a Bambara groundnut (Vigna subterranea). 

  • Any similar plant having underground tubers. 

How often have the words ding-dong and groundnut occurred in a corpus of books? (source: Google Ngram Viewer )