1. (noun)floodgate something that restrains a flood or outpouring Synonyms: head gate, sluicegate, sluice valve, penstock, water gate
2. (noun)sluicegate, sluice valve, floodgate, penstock, head gate, water gate regulator consisting of a valve or gate that controls the rate of water flow through a sluice Synonyms: sluice, sluice valve, water gate, head gate, sluiceway, sluicegate, penstock, floodgate