cantor vs post office

cantor

noun
  • A prayer leader in a Jewish service; a hazzan 

  • singer, especially someone who takes a special role of singing or song leading at a ceremony 

post office

noun
  • An organisation that delivers letters. 

  • A party game involving the exchange of kisses. 

  • A place (building, office, shop, or counter) concerned with the business of delivering letters, post or mail and selling stamps, etc. 

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