achene vs gourd

achene

noun
  • A small, dry, indehiscent fruit, containing a single seed, as in the buttercup. 

gourd

noun
  • A hard-shelled fruit from a plant in Lagenaria or Cucurbita. 

  • Any of the trailing or climbing vines producing fruit with a hard rind or shell, from the genera Lagenaria and Cucurbita (in Cucurbitaceae). 

  • The dried and hardened shell of such fruit, made into a drinking vessel, bowl, spoon, or other objects designed for use or decoration. 

  • loaded dice. 

  • Head. 

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