sweet orange vs sweet orange

sweet orange and sweet orange both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweet orange	Yes	No	No	No
sweet orange	Yes	No	No	No

sweet orange (noun)	sweet orange (noun)
orange with sweet juicy pulp; often has a thin skin	orange with sweet juicy pulp; often has a thin skin
probably native to southern China; widely cultivated as source of table and juice oranges	probably native to southern China; widely cultivated as source of table and juice oranges