hackberry vs nettle tree

hackberry and nettle tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
hackberry	Yes	No	No	No
nettle tree	Yes	No	No	No

As nouns, hackberry and nettle tree are synonyms defined as:

hackberry and nettle tree: any of various trees of the genus Celtis having inconspicuous flowers and small berrylike fruits

hackberry (noun)	nettle tree (noun)
small edible dark purple to black berry with large pits; southern United States	any of various trees of the genus Celtis having inconspicuous flowers and small berrylike fruits
any of various trees of the genus Celtis having inconspicuous flowers and small berrylike fruits