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' indicates a hidden word (a shortened or reduced extract from the clue).
'about' is a reversal indicator.
'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" .)