penstock /penˈstok/

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

• whelks
• whelky
• whelm
• whelmed
• whelming
• whelms
• whelp
• whelped
• whelping
• whelps
• whemmle
• whemmled
• whemmles
• whemmling
• when
• when all is said and done
• when as
• whenas
• whence
• whenceforth
• whences
• whencesoever
• whencever
• whene'er
• whenever