Assists in short time (7)
I believe the answer is:
seconds
'time' is the definition.
(I know this)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for seconds that I've seen before include "in a little while" , "not for long periods?" , "Short periods of time for supporters" , "Boxer's aides" , "Inferior goods" .)