Hoarder's problem (7)
I believe the answer is:
clutter
'hoarder's problem' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for clutter that I've seen before include "Untidy mess" , "Confused muddle of things" , "Untidy lot of objects in room" , "Clog up" , "Untidy state" .)