Doctor considered dropping over, and withdrew (9)
I believe the answer is:
rescinded
'withdrew' is the definition.
(rescind can mean to withdraw something)
'doctor considered dropping over and' is the wordplay.
I cannot really see how this works, but
'doctor' could be 'd' (eg in PhD, Doctor of Philosophy) and 'd' is located in the answer.
'over' could be 're' and 're' is found in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
(Another definition for rescinded that I've seen is " Revoked".)