trash heap vs junk heap

trash heap and junk heap both are nouns.

Word	Noun	Adjective	Verb	Adverb
trash heap	Yes	No	No	No
junk heap	Yes	No	No	No

As nouns, trash heap and junk heap are synonyms defined as:

trash heap and junk heap: an accumulation of refuse and discarded matter

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

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