mater vs momma

mater

noun
  • Mother. 

  • A meninx; the dura mater, arachnoid mater, or pia mater of the brain. 

  • Someone or something that mates. 

momma

noun
  • mother 

  • One's wife or girlfriend. 

  • A voluptuous woman. 

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