Surgeon has desire (4)
I believe the answer is:
urge
'desire' is the definition.
(I know that urge is a type of desire)
'surgeon has' is the wordplay.
'has' indicates the answer is hidden within the clue.
'URGE' is hidden in the letters of 'surgeon'.
(Other definitions for urge that I've seen before include "Encourage to proceed, drive onward" , "'Spur on, encourage (4)'" , "Advise earnestly, prod" , "Incite to action" , "Sudden desire" .)