buildup vs accumulation

buildup and accumulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
buildup	Yes	No	No	No
accumulation	Yes	No	No	No

As nouns, accumulation is a hypernym of buildup; that is, accumulation is a word with a broader meaning than buildup:

Other hypernyms of buildup include accrual, accruement.

As nouns, accumulation is a hypernym of buildup; that is, accumulation is a word with a broader meaning than buildup:

Other hypernyms of buildup include accretion.

buildup (noun)	accumulation (noun)
the act of building up an accumulation	the act of accumulating
highly favorable publicity and praise	several things grouped together or considered as a whole
the result of the process of accumulation	(finance) profits that are not paid out as dividends but are added to the capital base of the corporation
	an increase by natural growth or addition