Doctor behind rough outline (5)
I believe the answer is:
draft
'rough outline' is the definition.
'doctor behind' is the wordplay.
'doctor' becomes 'dr' ('Dr' can be a synonym of 'doctor').
'behind' becomes 'aft' ('aft' can be a synonym of 'behind').
'dr'+'aft'='DRAFT'
(Other definitions for draft that I've seen before include "form of conscription" , "Current of air or preliminary sketch" , "Formulate" , "conscript" , "book's outline" .)