gramma vs grandmum

gramma

noun
  • Something that is written. 

  • The subjects of reading, writing, and arithmetic. 

  • A variety of pumpkin, a cultivar of Cucurbita moschata. 

grandmum

noun
  • Grandmother. 

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