Contract's ending, then request a job (4)
I believe the answer is:
task
'a job' is the definition.
('task' can be a synonym of 'job')
'contract's ending then request' is the wordplay.
'ending' indicates one should take the final letters.
'then' says to put letters next to each other.
'request' becomes 'ask' ('ask' can be a synonym of 'request').
The final letter of 'contract' is 't'.
't'+'ask'='TASK'
(Other definitions for task that I've seen before include "Assignment" , "Job of work" , "Sort of force" , "Allocate work" , "Job, undertaking" .)