bitter orange tree vs marmalade orange

bitter orange tree and marmalade orange both are nouns.

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

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

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

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

bitter orange tree (noun)	marmalade orange (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