dipstick vs groundnut

dipstick

noun
  • A penis. 

  • A useless person of inferior intellect; a dipshit. 

  • A stick or rod used to measure the depth of a liquid. Often used to check the level at which a liquid in an opaque or inaccessible tank or reservoir stands; gauge. 

verb
  • To check (a person) for their understanding of something, as of a lesson, or attitude toward something. 

  • To measure the level of a fluid using a dipstick. 

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 dipstick and groundnut occurred in a corpus of books? (source: Google Ngram Viewer )