penstock /penˈstok/

1. A sluice
2. (in a hydroelectric or other plant) a valve-controlled water conduit

• watercolour
• watercolourist
• watercolourists
• watercolours
• water-cool
• water-cooled
• water cooler
• water coolers
• water-cooling
• water-cools
• water core
• water-core
• water-cores
• watercourse
• watercourses
• water cow
• water cows
• watercraft
• water crane
• water cranes
• watercress
• watercresses
• water culture
• water cultures
• water cure