chalice vs grail

chalice

noun
  • A large drinking cup, often having a stem and base and used especially for formal occasions and religious ceremonies. 

  • A kind of water-cooled pipe for smoking cannabis. 

grail

noun
  • The Holy Grail. 

  • Small particles of earth; gravel. 

  • One of the small feathers of a hawk. 

  • Something eagerly sought or quested for. 

  • A book of offices in the Roman Catholic Church; a gradual. 

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