Smart set regularly wasted stuff (4)
I believe the answer is:
sate
'stuff' is the definition.
(I've seen this in another clue)
'smart set regularly wasted' is the wordplay.
'regularly wasted' indicates alternate letters (letters removed at regular intervals).
'smart'+'set'='smartset'
The alternate letters of 'smartset' are 'SATE'.
(Other definitions for sate that I've seen before include "spicy meat" , "Malaysian dish" , "Fill to repletion" , "Satisfy to the full" , "Supply to full capacity" .)