fire brigade vs fire department

fire brigade and fire department both are nouns.

Word	Noun	Adjective	Verb	Adverb
fire brigade	Yes	No	No	No
fire department	Yes	No	No	No

As nouns, fire department is a hypernym of fire brigade; that is, fire department is a word with a broader meaning than fire brigade:

fire brigade: British name for a fire department
fire department: the department of local government responsible for preventing and extinguishing fires

fire brigade (noun)	fire department (noun)
a private or temporary organization of individuals equipped to fight fires	the department of local government responsible for preventing and extinguishing fires
British name for a fire department