Preliminary form of conscription (5)
I believe the answer is:
draft
I believe this clue is a double definition.
'preliminary' is the first definition.
(I've seen this before)
'form of conscription' is the second definition.
(I've seen this before)
(Other definitions for draft that I've seen before include "Current of air or preliminary sketch" , "Rough version" , "form of conscription" , "Formulate" , "plan outlined" .)