bittern
Concise Oxford English Dictionary © 2008 Oxford University Press:
bittern1 /ˈbɪtən/
▶noun a marshbird of the heron family with brown streaked plumage, noted for the male's deep booming call. [Botaurus stellaris (Eurasia), B. lentiginosus (N. America), and other species.]
– origin ME bitore, from OFr. butor, based on L. butio ‘bittern’ + taurus ‘bull’ (because of its call).
Concise Oxford English Dictionary © 2008 Oxford University Press:
bittern2 /ˈbɪt(ə)n/ (also bitterns)
▶noun a concentrated solution of various salts remaining after the crystallization of salt from seawater.
'bittern' also found in these Oxford entries:

