marmalade orange vs bitter orange

marmalade orange and bitter orange both are nouns.

Word	Noun	Adjective	Verb	Adverb
marmalade orange	Yes	No	No	No
bitter orange	Yes	No	No	No

As nouns, marmalade orange and bitter orange are synonyms defined as:

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

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

marmalade orange (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