service tree vs sorb apple tree

service tree and sorb apple tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
service tree	Yes	No	No	No
sorb apple tree	Yes	No	No	No

As nouns, service tree and sorb apple tree are synonyms defined as:

service tree and sorb apple tree: medium-sized European tree resembling the rowan but bearing edible fruit

Other synonyms of service tree include sorb apple, Sorbus domestica.

service tree (noun)	sorb apple tree (noun)
medium-sized European tree resembling the rowan but bearing edible fruit	medium-sized European tree resembling the rowan but bearing edible fruit
any of various North American trees or shrubs having showy white flowers and edible blue-black or purplish fruit