Pester doctor in case (6)
I believe the answer is:
molest
'pester' is the definition.
(I know that pester is a more specific form of the action bedevil)
'doctor in case' is the wordplay.
'doctor' becomes 'mo' (medical officer).
'in case' becomes 'lest' (I've seen this in another clue).
'mo'+'lest'='MOLEST'
(Other definitions for molest that I've seen before include "Handle roughly, torment" , "Disturb, interfere with" , "Ghost" , "Pester unpleasantly" , "Bug" .)