penstock

Estimated CEFR level: C2 — Proficiency

Estimated from word frequency; not an official CEFR classification.

Definition

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

Perhaps from pen (“an enclosure”) + stock.

(2) In water turbines, insert a large piece of scrap iron in the head of the penstock, just beyond the screening, so that water will carry the damaging material down to the plant equipment. — Simple Sabotage Field Manual, United States. Office of Strategic Services
This is the reason why, when he is sent to the spring for a pitcher of water, he is absent so long; for he stops to poke the frog that sits on the stone, or, if there is a penstock, to put his hand over the spout, and squirt the water a little while. — McGuffey's Fifth Eclectic Reader, William Holmes McGuffey

sluicegate, sluice valve, floodgate, head gate, water gate

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