Surgeon will do this around four, to see if it's functioning (9)
I believe the answer is:
operative
'functioning' is the definition.
(similar in meaning)
'surgeon will do this around four to see if it's' is the wordplay.
I cannot really understand how this works, but
'around' could be 'o' (a round letter) and 'o' is found in the answer.
'four' could be 'iv' (Roman numerals for four) and 'iv' is located in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for operative that I've seen before include "Having force - skilled worker" , "American detective" , "Efficient" , "Machinist - working" , "Functioning; worker" .)