Anas acuta vs pintail

Anas acuta and pintail both are nouns.

Word	Noun	Adjective	Verb	Adverb
Anas acuta	Yes	No	No	No
pintail	Yes	No	No	No

As nouns, Anas acuta and pintail are synonyms defined as:

Anas acuta and pintail: long-necked river duck of the Old and New Worlds having elongated central tail feathers

Other synonyms of Anas acuta include pin-tailed duck.

Anas acuta (noun)	pintail (noun)
long-necked river duck of the Old and New Worlds having elongated central tail feathers	long-necked river duck of the Old and New Worlds having elongated central tail feathers