bittern

• (Received Pronunciation) IPA^(key): /ˈbɪtən/
• (US) IPA^(key): /ˈbɪtəɹn/

Old French butor, from Gallo-Roman *butitaurus, a blend of Latin būtiō (“bittern”) and taurus (“bull, ox”).

bittern (plural bitterns)

1. Several bird species in the Botaurinae subfamily of the heron family Ardeidae.
   • 1819, Washington Irving, The Sketch Book, Rip Van Winkle:

     It is a great rock or cliff on the loneliest part of the mountains, and, … is known by the name of the Garden Rock. Near the foot of it is a small lake, the haunt of the solitary bittern, with water-snakes basking in the sun on the leaves of the pond-lilies which lie on the surface.

• bittern on Wikipedia.Wikipedia
• Appendix: Animals
• Appendix:English collective nouns
• bumble

From bitter with an unclear suffix, perhaps a dialect form of -ing.

bittern (uncountable)

1. The liquor remaining after halite (common salt) has been harvested from saline water (brine).
2. The saline substance added to soy milk to coagulate it as a primary step in the production of tofu.
   • 2019, “The Secrets of Tofu across Japan”, in Seasoning the Seasons‎, NHK World-Japan:

     Now we add the bittern.

3. (archaic) A very bitter compound of quassia, cocculus indicus, etc., used by fraudulent brewers in adulterating beer.

   (Can we find and add a quotation of Cooley to this entry?)

• Bittner, Britten