Citrus aurantium vs bitter orange

Citrus aurantium and bitter orange both are nouns.

Word	Noun	Adjective	Verb	Adverb
Citrus aurantium	Yes	No	No	No
bitter orange	Yes	No	No	No

As nouns, Citrus aurantium and bitter orange are synonyms defined as:

Citrus aurantium and bitter orange: any of various common orange trees yielding sour or bitter fruit; used as grafting stock

Other synonyms of Citrus aurantium include bigarade, bitter orange tree, marmalade orange, Seville orange, sour orange.

Citrus aurantium (noun)	bitter orange (noun)
any of various common orange trees yielding sour or bitter fruit; used as grafting stock	highly acidic orange used especially in marmalade
	any of various common orange trees yielding sour or bitter fruit; used as grafting stock