Smear running over many pages (5)
I believe the answer is:
reams
'many pages' is the definition.
Although both the answer and definition are plural nouns, I don't understand how they can define each other.
'smear running' is the wordplay.
'running' is an anagram indicator (the letters run around to different places).
'smear' is an anagram of 'REAMS'.
'over' acts as a link.
Can you help me to learn more?
(Other definitions for reams that I've seen before include "Large quantities (of paper?)" , "This much paperwork" , "Scrapes the barrel" , "Large quantity of written matter" , "a very large amount" .)