floodgate vs penstock

floodgate and penstock both are nouns.

Word	Noun	Adjective	Verb	Adverb
floodgate	Yes	No	No	No
penstock	Yes	No	No	No

As nouns, floodgate and penstock are synonyms defined as:

floodgate and penstock: regulator consisting of a valve or gate that controls the rate of water flow through a sluice

Other synonyms of floodgate include head gate, sluice valve, sluicegate, water gate.

floodgate (noun)	penstock (noun)
regulator consisting of a valve or gate that controls the rate of water flow through a sluice	conduit that carries a rapid flow of water controlled by a sluicegate
something that restrains a flood or outpouring	regulator consisting of a valve or gate that controls the rate of water flow through a sluice