Lots (of paper) (5)
I believe the answer is:
reams
'lots of paper' is the definition.
(a ream is a large amount of paper)
This is the entire clue.
(Other definitions for reams that I've seen before include "Scrapes the barrel" , "Lots of paper" , "This much paperwork" , "Large quantity of written matter" , "a very large amount" .)