attainment vs accomplishment

attainment and accomplishment both are nouns.

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

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

Other hypernyms of attainment include achievement.

As nouns, attainment and accomplishment are synonyms defined as:

attainment and accomplishment: an ability that has been acquired by training

Other synonyms of attainment include acquirement, acquisition, skill.

attainment (noun)	accomplishment (noun)
the act of achieving an aim	the action of accomplishing something
arrival at a new stage	an ability that has been acquired by training
an ability that has been acquired by training