bitter orange vs marmalade orange

bitter orange and marmalade orange both are nouns.

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

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

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

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

bitter orange (noun)	marmalade orange (noun)
highly acidic orange used especially in marmalade	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