Not much time for another helping (7)
I believe the answer is:
seconds
I believe this is a double definition.
'not much time' is the first definition.
(a second is a short amount of time)
'another helping' is the second definition.
(I've seen this in another clue)
'for' acts as a link.
(Other definitions for seconds that I've seen before include "in a minute!" , "Supports motion" , "Gives support to" , "More food!" , "Supporters - they are blemished" .)