American red plum vs wild plum

American red plum and wild plum both are nouns.

Word	Noun	Adjective	Verb	Adverb
American red plum	Yes	No	No	No
wild plum	Yes	No	No	No

As nouns, wild plum is a hypernym of American red plum; that is, wild plum is a word with a broader meaning than American red plum:

American red plum: wild plum trees of eastern and central North America having red-orange fruit with yellow flesh
wild plum: an uncultivated plum tree or shrub

Other hypernyms of American red plum include wild plum tree.

American red plum (noun)	wild plum (noun)
wild plum trees of eastern and central North America having red-orange fruit with yellow flesh	fruit of the wild plum of southern United States
	an uncultivated plum tree or shrub