Drive? A doctor with it will get on, I admitted (8)
I believe the answer is:
ambition
'drive?' is the definition.
(ambition is a kind of drive)
'a doctor with it will get on i admitted' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus**).
'with' is a charade indicator (letters next to each other).
'will get' means one lot of letters go next to another.
'admitted' is an insertion indicator.
'it'+'on'='iton'
'iton' enclosing 'i' is 'ition'.
'a'+'mb'+'ition'='AMBITION'
(Other definitions for ambition that I've seen before include "I'm in boat (anag.)" , "Cherished aspiration" , "Desire to succeed in the world" , "Urge to better oneself" , "Desire to achieve success" .)