marmalade orange vs sour orange

marmalade orange and sour orange both are nouns.

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

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

marmalade orange and sour 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, bitter orange tree, Citrus aurantium, Seville orange.

marmalade orange (noun)	sour 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