compost heap vs compost pile

compost heap and compost pile both are nouns.

Word	Noun	Adjective	Verb	Adverb
compost heap	Yes	No	No	No
compost pile	Yes	No	No	No

As nouns, compost heap and compost pile are synonyms defined as:

compost heap and compost pile: a heap of manure and vegetation and other organic residues that are decaying to become compost

compost heap (noun)	compost pile (noun)
a heap of manure and vegetation and other organic residues that are decaying to become compost	a heap of manure and vegetation and other organic residues that are decaying to become compost