oldwife vs Clangula hyemalis

oldwife and Clangula hyemalis both are nouns.

Word	Noun	Adjective	Verb	Adverb
oldwife	Yes	No	No	No
Clangula hyemalis	Yes	No	No	No

As nouns, oldwife and Clangula hyemalis are synonyms defined as:

oldwife and Clangula hyemalis: a common long-tailed sea duck of the northern parts of the United States

Other synonyms of oldwife include old squaw.

oldwife (noun)	Clangula hyemalis (noun)
tropical Atlantic fish	a common long-tailed sea duck of the northern parts of the United States
a common long-tailed sea duck of the northern parts of the United States