Sweet sort of filter (6)
I believe the answer is:
trifle
'sweet' is the definition.
(trifle is a kind of sweet)
'sort of filter' is the wordplay.
'sort of' indicates an anagram.
'filter' is an anagram of 'TRIFLE'.
(Other definitions for trifle that I've seen before include "Mess" , "Filter (anag.)" , "Small amount; dish" , "Small beer" , "Insignificant matter" .)