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' means one should take alternating 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" .)