\Stand"pipe`\, n.
1. (Engin.) A vertical pipe, open at the top, between a
   hydrant and a reservoir, to equalize the flow of water;
   also, a large vertical pipe, near a pumping engine, into
   which water is forced up, so as to give it sufficient head
   to rise to the required level at a distance.
2. (Steam Boiler) A supply pipe of sufficient elevation to
   enable the water to flow into the boiler, notwithstanding
   the pressure of the steam. --Knight.