first-year vs America

first-year is not a noun while America is a noun.

Word	Noun	Adjective	Verb	Adverb
first-year	No	Yes	No	No
America	Yes	No	No	No

first-year (noun)	America (noun)
	North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
	North America and South America and Central America

first-year (adjective)	America (adjective)
used of a person in the first year of an experience (especially in United States high school or college)