Plenty of support (5)
I believe the answer is:
piles
This might be a double definition.
'plenty' is the first definition.
(thesaurus)
'support' is the second definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'of' is the link.
Can you help me to learn more?
(Other definitions for piles that I've seen before include "complaint" , "Heaps" .)