Fix term's ultimate objective (4)
I believe the answer is:
mend
'fix' is the definition.
('mend' can be a synonym of 'fix')
'term's ultimate objective' is the wordplay.
'ultimate' suggests the final letters.
'objective' becomes 'end' (I've seen this before).
The last letter of 'term' is 'm'.
'm'+'end'='MEND'
(Other definitions for mend that I've seen before include "Put right" , "Make improvements" , "Heal" , "'Restore, fix (4)'" , "Return to health; repair" .)