American elm vs water elm

American elm and water elm both are nouns.

Word	Noun	Adjective	Verb	Adverb
American elm	Yes	No	No	No
water elm	Yes	No	No	No

As nouns, American elm and water elm are synonyms defined as:

American elm and water elm: large ornamental tree with graceful gradually spreading branches common in eastern North America

Other synonyms of American elm include rock elm, Ulmus americana, white elm.

American elm (noun)	water elm (noun)
large ornamental tree with graceful gradually spreading branches common in eastern North America	large ornamental tree with graceful gradually spreading branches common in eastern North America
	Eurasian elm closely resembling the American elm; thrives in a moist environment