Imprison Conservative? Good! (7)
I believe the answer is:
confine
'imprison' is the definition.
(I know that imprison is a more specific form of the action confine)
'conservative? good' is the wordplay.
'conservative?' becomes 'con' (abbreviation for Conservative).
'good' becomes 'fine' (both can mean satisfactory).
'con'+'fine'='CONFINE'
(Other definitions for confine that I've seen before include "Shut in" , "Keep within limits" , "pen" , "Imprison" , "Restrict (to an area)" .)