Rummage about for some time (6)
I believe the answer is:
forage
'rummage' is the definition.
(I've seen this before)
'for some time' is the wordplay.
'some time' becomes 'age' (an age is a period of time).
'for'+'age'='FORAGE'
'about' is the link.
(Other definitions for forage that I've seen before include "look around" , "Wander and feed" , "Search around for food" , "Seek for food" , "Plunder; rummage" .)