bittern

noun4

1. •
   Several bird species in the Botaurinae subfamily of the heron family Ardeidae.
2. •
   The liquor remaining after halite (common salt) has been harvested from saline water (brine).
3. •
   The saline substance added to soy milk to coagulate it as a primary step in the production of tofu.

   • Now we add the bittern. — 2019
4. •
   (no longer used) A very bitter compound of quassia, cocculus indicus, etc., used by fraudulent brewers in adulterating beer.