blackwater

noun5

1. •
   Water, especially in a river or other body of water, that has a naturally dark appearance.
2. •
   Water that contains dark organic matter such as loam or tannins.
3. •
   Water that is acidic and low in nutrients.
4. •
   Waste from domestic toilets; water containing fecal matter.
5. •
   Blackwater fever; malaria caused by Plasmodium falciparum.

   • She began talking of the way they had died – blackwater, malaria, a neglected appendix. — 1954