attainment vs arrival

attainment and arrival both are nouns.

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

As nouns, arrival is a hypernym of attainment; that is, arrival is a word with a broader meaning than attainment:

Other hypernyms of attainment include reaching.

attainment (noun)	arrival (noun)
the act of achieving an aim	accomplishment of an objective
arrival at a new stage	the act of arriving at a certain place
an ability that has been acquired by training	someone who arrives (or has arrived)