American bison vs buffalo

American bison and buffalo both are nouns.

Word	Noun	Adjective	Verb	Adverb
American bison	Yes	No	No	No
buffalo	Yes	No	Yes	No

As nouns, American bison and buffalo are synonyms defined as:

American bison and buffalo: large shaggy-haired brown bison of North American plains

Other synonyms of American bison include American buffalo, Bison bison.

American bison (noun)	buffalo (noun)
large shaggy-haired brown bison of North American plains	any of several Old World animals resembling oxen including, e.g., water buffalo, Cape buffalo
	large shaggy-haired brown bison of North American plains
	meat from an American bison

American bison (verb)	buffalo (verb)
	intimidate or overawe