Pronunciation: (pen'stok"), [key]
1. a pipe conducting water from a head gate to a waterwheel.
2. a conduit for conveying water to a power plant. See diag. under dam 1.
3. a sluicelike contrivance used to control the flow of water.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.