omasum vs psalterium

omasum

noun
  • The third compartment of the stomach of a ruminant; the lining of said compartment, regarded as a foodstuff. 

psalterium

noun
  • A psaltery (zither-like musical instrument) 

  • An omasum. 

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