Exclamation of disapproval about a job (4)
I believe the answer is:
task
'job' is the definition.
(I know that job can be written as task)
'exclamation of disapproval about a' is the wordplay.
'exclamation of disapproval' becomes 'tsk' (I've seen this in another clue).
'about' is an insertion indicator.
'tsk' placed around 'a' is 'TASK'.
(Other definitions for task that I've seen before include "Arduous bit of work" , "Difficult piece of work" , "Allocate work" , "exercise" , "Job, undertaking" .)