A whole lot of support (4)
I believe the answer is:
pile
I believe this is a double definition.
'a whole lot' is the first definition.
('pile' can be a synonym of 'whole lot')
'support' is the second definition.
(pile is a kind of support)
'of' acts as a link.
(Other definitions for pile that I've seen before include "large amount of money" , "Post" , "Nap of a carpet" , "Heap, carpet surface" , "Fortune" .)