heap vs cumulus

heap and cumulus both are nouns.

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

As nouns, heap and cumulus are synonyms defined as:

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

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

heap (adjective)	cumulus (adjective)
	of or related to cumulous clouds