Definition of gray water in US English:

gray water


  • The relatively clean waste water from baths, sinks, washing machines, and other kitchen appliances.

    Compare with black water
    • ‘After consumption, about 80 per cent of the water comes out as waste and this includes black water - toilet water - and grey water - bath water.’
    • ‘Systems that capture and reuse either rain water or so-called gray water from sinks and water fountains are proving to be cost effective.’
    • ‘The use of untreated grey water on your garden will degrade the fertility of your soil and damage your plants.’
    • ‘A one-week cruise can generate more than one million gallons of grey water - waste water from showers, galleys, and laundry - and 210,000 gallons of black water, or sewage.’
    • ‘Reed beds and mini wetlands are also used to clean grey water from baths and sinks so that the filtered water can feed vegetable patches or be used elsewhere in the garden.’