arrival vs newcomer

arrival and newcomer both are nouns.

Word	Noun	Adjective	Verb	Adverb
arrival	Yes	No	No	No
newcomer	Yes	No	No	No

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

Other hyponyms of arrival include early bird, latecomer.

arrival (noun)	newcomer (noun)
accomplishment of an objective	any new participant in some activity
the act of arriving at a certain place	a recent arrival
someone who arrives (or has arrived)