1. regulator consisting of a valve or gate that controls the rate of water flow through a sluice • Syn: sluicegate, sluice valve, floodgate, penstock, water gate • Hypernyms: regulator • Part Holonyms: sluice, sluiceway, penstock 2. a gate upstream from a lock or canal that is used to control the flow of water at the upper end • Hypernyms: gate