fire hydrant vs hydrant

fire hydrant and hydrant both are nouns.

Word	Noun	Adjective	Verb	Adverb
fire hydrant	Yes	No	No	No
hydrant	Yes	No	No	No

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

fire hydrant: an upright hydrant for drawing water to use in fighting a fire
hydrant: a discharge pipe with a valve and spout at which water may be drawn from the mains of waterworks

fire hydrant (noun)	hydrant (noun)
an upright hydrant for drawing water to use in fighting a fire	a discharge pipe with a valve and spout at which water may be drawn from the mains of waterworks
	a faucet for drawing water from a pipe or cask