bastion vs quarterdeck

bastion

noun
  • A projecting part of a rampart or other fortification. 

  • A well-fortified position; a stronghold or citadel. 

  • A person, group, or thing, that strongly defends some principle. 

  • Any large prominence; something that resembles a bastion in size and form. 

verb
  • To furnish with a bastion. 

quarterdeck

noun
  • The aft part of the upper deck of a ship; normally reserved for officers 

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