water oak vs possum oak

water oak and possum oak both are nouns.

Word	Noun	Adjective	Verb	Adverb
water oak	Yes	No	No	No
possum oak	Yes	No	No	No

As nouns, water oak and possum oak are synonyms defined as:

water oak and possum oak: relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil

Other synonyms of water oak include Quercus nigra.

water oak (noun)	possum oak (noun)
relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil	relatively tall deciduous water oak of southeastern United States often cultivated as a shade tree; thrives in wet soil