cumulation vs heap

cumulation and heap both are nouns.

Word	Noun	Adjective	Verb	Adverb
cumulation	Yes	No	No	No
heap	Yes	No	Yes	No

As nouns, cumulation and heap are synonyms defined as:

Other synonyms of cumulation include agglomerate, cumulus, mound, pile.

cumulation (noun)	heap (noun)
a collection of objects laid on top of each other	a car that is old and unreliable
	a collection of objects laid on top of each other
	(often followed by `of') a large number or amount or extent