penstock vs water gate

penstock and water gate both are nouns.

Word	Noun	Adjective	Verb	Adverb
penstock	Yes	No	No	No
water gate	Yes	No	No	No

As nouns, penstock and water gate are synonyms defined as:

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

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

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