grizzly bear vs Ursus horribilis

grizzly bear and Ursus horribilis both are nouns.

Word	Noun	Adjective	Verb	Adverb
grizzly bear	Yes	No	No	No
Ursus horribilis	Yes	No	No	No

As nouns, grizzly bear and Ursus horribilis are synonyms defined as:

grizzly bear and Ursus horribilis: powerful brownish-yellow bear of the uplands of western North America

Other synonyms of grizzly bear include grizzly, silver-tip, silvertip, Ursus arctos horribilis.

grizzly bear (noun)	Ursus horribilis (noun)
powerful brownish-yellow bear of the uplands of western North America	powerful brownish-yellow bear of the uplands of western North America