Bogged down setter about to punch boss (5)
I believe the answer is:
mired
'bogged down' is the definition.
('mire' can be a synonym of 'bog down')
'setter about to punch boss' is the wordplay.
'setter' becomes 'I' (the person who set this crossword).
'about' becomes 're' (regarding).
'to punch' indicates putting letters inside (some letters punch a hole in others).
'boss' becomes 'MD' (short for managing director).
'i'+'re'='ire'
'ire' placed into 'md' is 'MIRED'.
(Other definitions for mired that I've seen before include "Bogged down" , "Sunk in deep mud" , "Stuck in the mud" , "covered in muck" .)