marmalade orange vs bitter orange tree

marmalade orange and bitter orange tree both are nouns.

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

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

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

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

marmalade orange (noun)	bitter orange tree (noun)
any of various common orange trees yielding sour or bitter fruit; used as grafting stock	any of various common orange trees yielding sour or bitter fruit; used as grafting stock