Hispanic American vs Spanish American

Hispanic American and Spanish American both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hispanic American	Yes	No	No	No
Spanish American	Yes	No	No	No

As nouns, Hispanic American and Spanish American are synonyms defined as:

Hispanic American and Spanish American: an American whose first language is Spanish

Other synonyms of Hispanic American include Hispanic.

Hispanic American (noun)	Spanish American (noun)
an American whose first language is Spanish	an American whose first language is Spanish