Nana vs gammy

Nana

name

  • One's grandmother. 

  • A governess. 

  • A Japanese female given name from Japanese 

gammy

noun

  • Grandmother. 

  • A blowjob; fellatio. 

adj

  • Injured, or not functioning properly (with respect to legs). 

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