Make a change in professional terms (5)
I believe the answer is:
alter
'make a change' is the definition.
(I've seen this in another clue)
'in professional terms' is the wordplay.
'in' indicates a hidden word.
'ALTER' is hidden within 'professional terms'.
(Other definitions for alter that I've seen before include "Make changes to" , "Metamorphose" , "convert" , "Amend" , "Change, maybe later" .)