bison vs wisent

bison and wisent both are nouns.

Word	Noun	Adjective	Verb	Adverb
bison	Yes	No	No	No
wisent	Yes	No	No	No

As nouns, wisent is a hyponym of bison; that is, wisent is a word with a more specific, narrower meaning than bison:

bison: any of several large humped bovids having shaggy manes and large heads and short horns
wisent: European bison having a smaller and higher head than the North American bison

Other hyponyms of bison include American bison, American buffalo, Bison bison, buffalo, aurochs, Bison bonasus.

bison (noun)	wisent (noun)
any of several large humped bovids having shaggy manes and large heads and short horns	European bison having a smaller and higher head than the North American bison