garbage heap vs junk pile

garbage heap and junk pile both are nouns.

Word	Noun	Adjective	Verb	Adverb
garbage heap	Yes	No	No	No
junk pile	Yes	No	No	No

As nouns, garbage heap and junk pile are synonyms defined as:

garbage heap and junk pile: an accumulation of refuse and discarded matter

Other synonyms of garbage heap include junk heap, refuse heap, rubbish heap, scrapheap, trash heap, trash pile.

garbage heap (noun)	junk pile (noun)
an accumulation of refuse and discarded matter	an accumulation of refuse and discarded matter