armoury vs chain mail

armoury

noun
  • A collection of weapons and materiel. 

  • Heraldry 

  • A place where arms are kept, an arsenal. 

  • A place where arms are made. 

  • The manufacture of armour and arms; arming, armouring. 

chain mail

noun
  • A flexible defensive armor, made of a mesh of interlinked metal rings. 

  • A chain letter. 

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