Greywater – waste water from non-toilet plumbing fixtures such as showers, basins and taps. Grey water comes out of taps
The greyhound loved tap dancing (grey is associated with taps).
Greywater – Comes out of taps
NOTE: Greywater can be compared to blackwater which doesn't come out of taps but comes out of toilets. Blackwater contains faecal matter (poo) or urine (wee).
Treated greywater can be used for toilet flushing or for watering plants in the garden.