Seville orange vs bitter orange tree

Seville orange and bitter orange tree both are nouns.

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

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

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

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

Seville orange (noun)	bitter orange tree (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