beachhead vs accomplishment

beachhead and accomplishment both are nouns.

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

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

beachhead: an initial accomplishment that opens the way for further developments
accomplishment: the action of accomplishing something

Other hypernyms of beachhead include achievement.

beachhead (noun)	accomplishment (noun)
an initial accomplishment that opens the way for further developments	the action of accomplishing something
a bridgehead on the enemy's shoreline seized by an amphibious operation	an ability that has been acquired by training