1.  scrapheap(n = noun.location) garbage heap, junk heap, junk pile, refuse heap, rubbish heap, trash heap, trash pile - an accumulation of refuse and discarded matter;
is a kind of dump, dumpsite, garbage dump, rubbish dump, trash dump, waste-yard, wasteyard

2.  scrapheap(n = noun.group) - pile of discarded metal;
is a kind of agglomerate, cumulation, cumulus, heap, mound, pile