Empty talk in managing a side (3)
I believe the answer is:
gas
'empty talk' is the definition.
(I've seen this before)
'in managing a side' is the wordplay.
'in' indicates a hidden word.
'GAS' is hidden in the letters of 'managing a side'.
(Other definitions for gas that I've seen before include "Wind" , "idle chit-chat" , "could be embarrassing for American" , "Something that is neither solid not liquid" , "Something delightful" .)