oryx vs Oryx gazella

oryx and Oryx gazella both are nouns.

Word	Noun	Adjective	Verb	Adverb
oryx	Yes	No	No	No
Oryx gazella	Yes	No	No	No

As nouns, Oryx gazella is a hyponym of oryx; that is, Oryx gazella is a word with a more specific, narrower meaning than oryx:

oryx: large African antelope with long straight nearly upright horns
Oryx gazella: large South African oryx with a broad black band along its flanks

Other hyponyms of oryx include gemsbok, gemsbuck.

oryx (noun)	Oryx gazella (noun)
large African antelope with long straight nearly upright horns	large South African oryx with a broad black band along its flanks