fire brigade vs fire department

fire brigade

noun
  • An organization, often part of a local government, whose purpose is preventing and putting out fires. 

  • A group of people within a corporation or industrial site, organized for the purpose of putting out fires, usually in addition to their normal job. 

  • A trained unit that can be rapidly deployed to deal with any difficult situation. 

fire department

noun
  • An organization, often part of a local government, whose purpose is preventing and putting out fires. May provide other emergency services as well. 

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