Complaint - coffee break about to be shortened (4)
I believe the answer is:
beef
'complaint' is the definition.
(beef can mean a complaint or objection)
'coffee break about to be shortened' is the wordplay.
'to be shortened' says the answer is hidden in the clue (a shortened or reduced extract from the clue).
'about' shows that the letters should be reversed in order.
'feeb' can be found hidden inside 'coffee break'.
'feeb' in reverse letter order is 'BEEF'.
(Other definitions for beef that I've seen before include "nickname of US State" , "Argument" , "See 24" , "Brawn; grumble" , "Complain; meat" .)