bigarade vs Seville orange

bigarade and Seville orange both are nouns.

Word	Noun	Adjective	Verb	Adverb
bigarade	Yes	No	No	No
Seville orange	Yes	No	No	No

As nouns, bigarade and Seville orange are synonyms defined as:

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

bigarade (noun)	Seville 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