Greenland caribou vs caribou

Greenland caribou and caribou both are nouns.

Word	Noun	Adjective	Verb	Adverb
Greenland caribou	Yes	No	No	No
caribou	Yes	No	No	No

As nouns, Greenland caribou and caribou are synonyms defined as:

Greenland caribou and caribou: Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America

Other synonyms of Greenland caribou include Rangifer tarandus, reindeer.

Greenland caribou (noun)	caribou (noun)
Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America	Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America