from The Century Dictionary and Cyclopedia
- n. A valve through which water or other fluid may be blown out or drained away.
- n. The blow-off valve in a steam-boiler through which water and mud, or precipitated solids in the water, can be blown to waste.
- n. The valve or gate in the waste-weir or sluice of a dam, through which water may be wasted or allowed to flow out of the pond above the dam to relieve the latter.
Sorry, no etymologies found.