coffee tree vs coffee

coffee tree and coffee both are nouns.

Word	Noun	Adjective	Verb	Adverb
coffee tree	Yes	No	No	No
coffee	Yes	No	No	No

As nouns, coffee tree and coffee are synonyms defined as:

coffee tree and coffee: any of several small trees and shrubs native to the tropical Old World yielding coffee beans

coffee tree (noun)	coffee (noun)
any of several small trees and shrubs native to the tropical Old World yielding coffee beans	a medium brown to dark-brown color
	a beverage consisting of an infusion of ground coffee beans
	a seed of the coffee tree; ground to make coffee
	any of several small trees and shrubs native to the tropical Old World yielding coffee beans