Rocky Mountain sheep vs bighorn

Rocky Mountain sheep and bighorn both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rocky Mountain sheep	Yes	No	No	No
bighorn	Yes	No	No	No

As nouns, Rocky Mountain sheep and bighorn are synonyms defined as:

Rocky Mountain sheep and bighorn: wild sheep of mountainous regions of western North America having massive curled horns

Other synonyms of Rocky Mountain sheep include bighorn sheep, cimarron, Ovis canadensis, Rocky Mountain bighorn.

Rocky Mountain sheep (noun)	bighorn (noun)
wild sheep of mountainous regions of western North America having massive curled horns	wild sheep of mountainous regions of western North America having massive curled horns