noncitizen vs metic

noncitizen and metic both are nouns.

Word	Noun	Adjective	Verb	Adverb
noncitizen	Yes	No	No	No
metic	Yes	No	No	No

As nouns, metic is a hyponym of noncitizen; that is, metic is a word with a more specific, narrower meaning than noncitizen:

noncitizen: a person who comes from a foreign country; someone who does not owe allegiance to your country
metic: an alien who paid a fee to reside in an ancient Greek city

Other hyponyms of noncitizen include au pair, deportee, exile, gringo, import, importee.

noncitizen (noun)	metic (noun)
a person who comes from a foreign country; someone who does not owe allegiance to your country	an alien who paid a fee to reside in an ancient Greek city